2010-22826. Testing Method of Pressed and Toughened (Specially Tempered) Glassware

AGENCY:

U.S. Customs and Border Protection, Department of Homeland Security.

ACTION:

Notice of method CBP uses to test pressed and toughened (specially tempered) glassware for tariff classification purposes.

SUMMARY:

This document adopts modifications to the test method currently applied by U.S. Customs and Border Protection (“CBP”) for the testing of pressed and toughened (specially tempered) glassware, as set forth in Treasury Decision (T.D.) 94-26 which was published in the Federal Register on March 22, 1994. This document sets forth revised criteria for interpreting the results obtained from the cutting test for opaque glassware and provides an interpretation of breakage for that test. In addition, this document reinstates a previously used testing method, the center punch test, and provides a description of the center punch apparatus to be used for that test. The final CBP test method for pressed and toughened (specially tempered) glassware for tariff classification purposes is set forth in its entirety in this document.

DATES:

CBP will begin applying this revised test method on glassware entered, or withdrawn from warehouse, for consumption effective October 14, 2010.

FOR FURTHER INFORMATION CONTACT:

Margaret Chinn, Office of Information and Technology, Laboratories and Scientific Services, [phone]; Stephen Cassata, Office of Information and Technology, Laboratories and Scientific Services, [phone].

SUPPLEMENTARY INFORMATION:

Background

This document sets forth modifications to the criteria utilized by U.S. Customs and Border Protection (“CBP”) to test certain glassware articles to determine whether they are “pressed and toughened (specially tempered)” for tariff classification purposes under the Harmonized Tariff Schedule of the United States (“HTSUS”). The glassware articles subject to these testing procedures are generally imported into the United States under subheadings 7013.28.05, 7013.37.05, 7013.42.10, 7013.49.10, and 7013.99.20, HTSUS. Articles of “safety glass, consisting of toughened (tempered) or laminated glass” that are normally imported under heading 7007, HTSUS (e.g., architectural plate glass and vehicle windshields), are not within the purview of this final notice.

Information regarding the apparatus used, glass sample preparation, and the methods employed by CBP to test glassware articles to determine whether they are pressed and toughened (specially tempered) was previously set forth in the Federal Register (59 FR 13531, March 22, 1994; see also, 59 FR 16895, April 8, 1994, correcting “T.D. 94-25” to “T.D. 94-26”). Under T.D. 94-26, photographic equipment, polariscopes, tile saws (or similar table-mounted circular saws), or other apparatus and supplies, such as calipers, ovens, and water baths, can be used to test subject glassware articles. With respect to sample preparation, T.D. 94-26 states that a representative number of samples should be analyzed but recognizes the possibility that only one sample may be available for testing.

The method to be used for the testing of pressed and toughened (specially tempered) glassware under T.D. 94-26 consists of three tests. They are the “macroscopic analysis,” “thermal shock test,” and “evaluation of temper.” The evaluation of temper test consists of a polariscopic examination for transparent or translucent glassware and a cutting test for opaque glassware. The proposed modification of the test method was limited to the cutting test for opaque glassware.

Proposed Modifications

On January 9, 2008, CBP published a notice in the Federal Register (73 FR 1640) which proposed modifications to the method applied for the testing of pressed and toughened (specially tempered) glassware as set forth in T.D. 94-26 and solicited public comments. The notice proposed modifications to the cutting test for opaque glassware but did not propose changes to the testing procedures used for the macroscopic analysis test, thermal shock test, and polariscopic examination aspect of the evaluation of temper test. The notice also proposed to reinstate the “center punch test” and provided a description of the center punch apparatus that would be used for the proposed test. Finally, the notice proposed to allow for the optional use of additional tests by CBP that would be used only to verify the results obtained from the other testing procedures. The modifications set forth in the January 9, 2008, notice are described in greater detail below.

Proposed Changes to Cutting Test for Opaque Glassware

The cutting test for opaque glassware is used for opaque glassware and translucent glassware that cannot be examined polariscopically because they do not transmit adequate polarized light. In the notice of January 9, 2008, it was proposed to revise the criteria used to interpret the results obtained from the cutting test for opaque glassware. In addition, it was proposed to add an interpretation of breakage in the test because the guidelines set forth in T.D. 94-26 did not clearly explain how breakage should be interpreted. Under the proposal, CBP would interpret the test such that the presence of “some” dicing or crazing would be sufficient to determine that a glass article has been specially tempered for tariff classification purposes. Under this standard, “some” would be considered to be any diced, crazed (gravel that remains tenuously in contact with neighboring pieces), or graveled (presence of small cubes of approximately equal dimensions on all six sides) fragment yielded from the cut sample that is more than just a fugitive diced, crazed, or graveled fragment. In addition, it was proposed to remove the references to tempered soda lime, borosilicate, and fluorosilicate glass that are currently in the test because the composition of the glass is not relevant for testing purposes.

Proposal to Add Center Punch Test

The notice of January 9, 2008, also proposed to reinstate the center punch test. It was noted in the proposal that it is dangerous for an analyst to perform the cutting test on a sample that is less than five inches in diameter or five inches wide and that it would be preferable to use the center punch test in these cases. The center punch apparatus to be used to perform the test would be a slender tool approximately 8 to 12 inches in length with one end tapered to a point. The tool would be long enough to allow for its insertion into tall-form tumblers and other articles of similar shape while permitting the nonpointed end to extend above the rim. This would be necessary for handling and safety purposes when performing the center punch test. The pointed end of the center punch would not be so sharp so as to chip the glassware on contact without applying pressure.

In order to perform the center punch test under the proposal, a sample would initially be set on a solid and level surface. An analyst would then place the pointed end of the center punch vertically against the inside center bottom or heel of the article. The analyst would strike the dull end of the punch with a hammer, using blows of gradually increasing severity until breakage occurs. The breakage pattern, approximate number, and relative shape and size of the fragments would then be noted. Thereafter, the breakage pattern and/or typical fragments would be photographed. It would only be necessary for the broken sample to exhibit “some” dicing, crazing, or graveling in order to be considered tempered for CBP's classification purposes. “Some” would be considered to be any diced, crazed, or graveled fragments yielded by the broken sample that are more than just fugitive diced, crazed, or graveled fragments.

Proposal to Add Option to Use Additional Tests

In addition, the notice of January 9, 2008, proposed to provide for the optional use of additional tests by CBP. The additional tests would be used by CBP only to verify the results obtained from the other testing procedures. It was stated that the additional tests would facilitate the overall testing process by ensuring that the results obtained from the other testing procedures are accurate.

Discussion of Comments

Comments were solicited in the notice of January 9, 2008, and the comment period closed on March 17, 2008. One commenter responded during this time period on behalf of two clients, a manufacturer and separate importer of tempered glassware. The commenter submitted two letters, a set of photographs, and a series of ten short videos. A description of the comments and other material in the submission, as well as CBP's related analysis, follows.

Comment:

The commenter asserts that the standard proposed for the testing of pressed and toughened (specially tempered) glassware set forth in the notice of January 9, 2008, would produce erroneous results and would not meet certain parameters established by the courts for testing methodology.

CBP's Response:

The commenter submitted photographs and videos in an attempt to demonstrate that CBP's proposed testing method for the testing of pressed and toughened (specially tempered) glassware would produce erroneous results. As discussed further below, however, CBP does not find the commenter's submission persuasive in this regard because the proposed modifications to the testing method would actually introduce a higher degree of accuracy into the testing process. In addition, CBP believes that this testing method would withstand judicial scrutiny because the generally accepted methods in the standard are accurate, testable, and have been subject to peer review and publication.

Comment:

The commenter states that the center punch test is not a useful or reliable test for tempered glassware and opposes its reinstatement by CBP. The commenter expressed its concern that CBP did not make clear in the notice of January 9, 2008, whether the center punch test would be used in lieu of, or in addition to, the cutting test. Moreover, if the center punch is intended to be used in addition to the cutting test, the commenter questions the relative weight CBP will assign to each test in determining whether an item is considered tempered.

CBP's Response:

CBP's position is that the center punch test is useful and reliable, and CBP has determined that its reinstatement into the method for the testing of pressed and toughened (specially tempered) glassware is necessary. In support of this determination, CBP recognizes that the reinstatement of the center punch test will provide CBP analysts with a test that can be used in cases where the cutting test yields inconclusive results or when it would be dangerous to use the cutting test because of the dimensions of the sample.

As noted above, one instance where the center punch test will be used is when the cutting test yields inconclusive results. In this situation, the results of the center punch test will be interpreted in conjunction with the results of the cutting test in order to make the correct classification determination. CBP believes this additional test is required because the CBP Laboratory occasionally tests samples that break into several large pieces when subjected to the cutting test. Without the benefit of a second test to confirm whether the tested glassware is actually pressed and toughened (specially tempered) in these cases, the analyst is constrained under the current standard to classify the article as “tempered” even though there may be doubts as to whether the article is actually tempered. Accordingly, the revised standard set forth in this document will afford the CBP analyst with the opportunity to utilize the center punch test in cases where the results of the cutting test are inconclusive (i.e., if the sample breaks into several large pieces when subjected to the cutting test).

The second instance where the center punch test will be employed under the proposed revised method is cases where an article is too small to safely analyze with the cutting test. CBP believes this is necessary because the integrity of a tempered glassware article can fail during a cutting test, potentially resulting in serious injury to the CBP analyst. Accordingly, the revised method will afford the analyst the opportunity to utilize the center punch test on articles considered “too small” to safely perform a cutting test. The revised method will make clear that glassware articles considered too small to analyze safely with a cutting test will be those that are smaller than five inches in diameter or five inches wide. If a glassware article is smaller than five inches in diameter or five inches wide and the analyst chooses to use the center punch test, a cutting test will not be performed on the article and the results obtained from the center punch test will be considered independently. Results obtained from the center punch test in these situations will be interpreted in the same manner as results obtained from the cutting test.

Comment:

The commenter states that the proposed breakage analysis for tempered glassware subjected to the cutting or center punch test (particularly fluorosilicate which has characteristics unique to its crystalline structure) is too subjective and in many instances would result in an erroneous conclusion that a tempered article is not tempered. With respect to the proposed breakage analysis, the commenter specifically states that both annealed and tempered fluorosilicate plates which are subjected to the center punch test break into small pizza-shaped pieces, the only real difference being that the tempered plates take more force to break and yield somewhat smaller pizza-shaped pieces. In addition, other types of articles may react differently when subjected to the center punch test. For example, a tempered mug which is subjected to the center punch test may break into irregular pieces smaller than those of an annealed mug.

The commenter indicates that their client has performed repeated center punch tests on the full range of fluorosilicate articles which they manufacture and have confirmed that other than the differences in the appearance of the pieces noted above, they did not observe dicing or crazing of tempered fluorosilicate glass. The commenter submitted various photographs and ten short videos in order to demonstrate the difficulty associated with classifying glass as tempered or non-tempered based on breakage patterns. The commenter states that the photographs depict annealed and tempered fluorosilicate (opal) and soda lime plates subjected to the center punch test. The commenter indicates that of the ten videos submitted, two are of the center punch test performed on tempered fluorosilicate glass plates; two are of the center punch test performed on annealed fluorosilicate glass plates; one is of the center punch test performed on a tempered soda lime glass plate; one is of the center punch test performed on an annealed soda lime glass plate; one is of a hammer striking a tempered fluorosilicate plate; one is of a hammer striking an annealed fluorosilicate plate; one is of the center punch test performed on a tempered fluorosilicate mug; and one is of the center punch test performed on an annealed fluorosilicate mug.

The commenter believes that the photographs and videos prove that the breakage differences resulting when the center punch test is performed on tempered versus annealed glass can be so subtle as to be virtually non-existent. The commenter specifically notes that tempered fluorosilicate glass plates will not exhibit any dicing, graveling, or crazing when cut or center punched. In addition, the commenter states that dicing, crazing, or graveling are characteristics that are generally exhibited in heat-treated flat glass, not flat glassware. The commenter contends that because tempered dinnerware is very different in shape and thickness, dicing, crazing or graveling does not ordinarily occur in soda lime glass dinnerware and never occurs in tempered fluorosilicate glass dinnerware. Moreover, the commenter states that there is no evidence that glass dinnerware should dice, craze, or gravel when cut.

CBP's Response:

CBP disagrees with the commenter's statement that the analysis of breakage patterns for tempered glassware subjected to the cutting or center punch tests is too subjective to be deemed reliable. In addition, CBP notes that some degree of temper must be visually evident for a glassware article to be considered “toughened (specially tempered)” and also maintains that a tempered glassware article will craze, dice, or gravel when broken.

CBP notes that the degree of temper in glassware is roughly equivalent to the strength increase of the glass produced by the compression on the outside of the article and that this increase in compression is compensated for by a greater amount of internal tension. CBP's view is that, at some point, the appearance of dicing indicates a certain amount of achievement of strength through tempering and that progressively smaller fragments corresponds to even higher levels of temper. The factor affecting whether an interior crack branches into other fractures is principally the state of the stress at those interior points through which the crack propagates. CBP's criterion for “toughened (specially tempered)” translates roughly into the requirement that the state of tensile strength in the interior of the article due to tempering should be high enough to produce this branching which is exhibited by visible dicing, crazing, or graveling during breakage through at least part of the article. In this respect, whether it is flat glass or dinner glassware, it is a common axiom that a tempered glassware article will craze, dice, or gravel when it breaks.

With respect to the photographic and video evidence submitted by the commenter, CBP initially agrees that in some cases the tempered glassware depicted in the submissions does not appear to craze, dice, or gravel when impacted with a center punch. However, it is noted that no evidence was submitted to demonstrate that the glassware subjected to testing in the submissions was, in fact, tempered. In addition, CBP notes that the experiments were not technically accurate because only a hammer was used in some of the tests. Accordingly, the criteria for interpreting breakage for the cutting test for opaque glassware and the reinstated center punch test, as set forth in the January 9, 2008, notice, will not be eliminated from the revised method for the testing of pressed and toughened (specially tempered) glassware.

Comment:

The commenter states that CBP's proposal to use additional tests to verify the results of the other tests is improper because tests that are never disclosed or described cannot be properly scrutinized. In addition, the commenter states that CBP has not explained what weight would be assigned to the additional tests for purposes of applying the testing methodology.

CBP's Response:

CBP agrees that the verification of additional test results would be problematic for the reasons the commenter provides. Accordingly, additional tests will not be used to verify the results of the other tests, as reflected in the revised method to be applied for the testing of pressed and toughened (specially tempered) glassware which is set forth below.

Conclusion

After analyzing the comments and other material contained in the submission discussed above and further review of the matter, CBP has decided to adopt, except for the use of additional tests as discussed in the comment section above, the modifications to the test method used by CBP for the testing of pressed and toughened (specially tempered) glassware as proposed in the notice of January 9, 2008 (73 FR 1640) for the cutting test for opaque glassware and for the reinstatement of the center punch test for articles less than five inches in diameter and for inconclusive results from the cutting test. In addition, this document inserts a new section, “Scope and Field of Application”, into the test method. This new section merely clarifies that the method employs macroscopic analysis, thermal shock testing, and evaluation of temper. This new section also clarifies that pressed and toughened (specially tempered) glassware articles are normally imported under subheadings 7013.28.05, 7013.37.05, 7013.42.10, 7013.49.10, and 7013.99.20, HTSUS, and that articles normally imported under heading 7007, HTSUS, such as windshields, are not within the purview of the method. Finally, this document makes other minor editorial changes to the test method. The revised test method, set forth in its entirety below, will be employed by CBP on glassware entered, or withdrawn from warehouse, for consumption on or after 30 days from the date of publication of this document in the Federal Register.

TESTING METHOD OF PRESSED AND TOUGHENED (SPECIALLY TEMPERED) GLASSWARE

SAFETY PRECAUTION: CERTAIN PROCEDURES DESCRIBED IN THIS METHOD POSE A POTENTIAL HAZARD TO PERSONNEL FROM THE PROXIMITY TO OR HANDLING OF BREAKING OR BROKEN GLASS. THIS METHOD SHALL NOT BE UNDERTAKEN WITHOUT SUPERVISORY CONCURRENCE THAT ADEQUATE PRECAUTIONS FOR PERSONAL SAFETY HAVE BEEN IMPLEMENTED.

SCOPE AND FIELD OF APPLICATION

This method employs macroscopic analysis, thermal shock testing, and evaluation of temper to determine if a glassware item has been pressed and toughened (specially tempered) for U.S. Customs and Border Protection (CBP)'s tariff classification purposes.

These glassware articles are normally imported under subheading numbers 7013.28.05, 7013.37.05, 7013.42.10, 7013.49.10, and 7013.99.20 of the Harmonized Tariff Schedule of the United States (HTSUS). Articles of “safety glass, consisting of toughened (tempered) * * * glass,” normally imported under heading 7007 of the HTSUS, (e.g., vehicle windshields) are not within the purview of this method.

1. APPARATUS:

Photographic Equipment:

A camera (equipped with flash or supplemented by adequate lighting) is recommended for making a permanent record of unusual samples and test results.

Polariscope:

The basic instrument consists of a light source, a polarizer, and an analyzer. The addition of a full-wave retardation, or tint, plate permits observation of color-enhanced stress patterns. Ideally, the working space, or distance between the polarizer and the analyzer, should be large enough to accommodate samples ranging up to eight inches in height.

Tile Saw (or Similar Table-Mounted Circular Saw):

A tile saw having a cutting head which can be adjusted horizontally and vertically and which is equipped with an 8 to 12 inch diameter continuous rim diamond blade designed for wet cutting glass is adequate for testing opaque glassware articles.

Center Punch:

The center punch is a slender tool having one end tapered to a point. The tool should be approximately 8″; to 12″ in length to permit insertion into tall-form tumblers and other articles of similar shape while the nonpointed end extends above the rim. This is necessary for ease of handling and for safety while performing the center punch test. The pointed end of the center punch should not be sufficiently sharp so as to chip the glassware on contact without the application of pressure.

Other Apparatus and Supplies:

The method requires various common laboratory articles such as a caliper or similar device for measuring the diameter of the opening and the maximum inside diameter of the sample, an oven, a water bath, and other equipment and supplies. Appropriate safety devices and personal protective equipment are also required.

2. PREPARATION OF THE SAMPLE

When available a representative number of samples should be analyzed. However, it is recognized that for any of several reasons, e.g., cost of the item, only a limited number of samples may be submitted for analysis. The possibility exists that only one sample may be available for testing.

3. ANALYSIS PROCEDURES

The following procedures may be conducted in whatever order the analyst deems is appropriate for the particular sample being examined. The test protocol should be terminated at the point that a sample fails to meet any of the key criteria, i.e., “pressed”, “toughened”, or “specially tempered.”

Evaluation for Determination if an Article Has Been Pressed

3.1 Macroscopic Analysis:

3.1.1 Visual Inspection:

Inspect the sample for the following:

• Identifying marks, labels, sizes, etc., especially those that may have been caused by a push-up valve and a mold that have been pressed into the article;
• The style (stemware, tumbler, bowl, plate, etc.);
• The presence of ribs, handles, flutes, etc.;
• The size of the rim or opening, if applicable;
• The size of the most bulbous portion of the article;
• Any other unusual characteristics (e.g., chips, cracks).

Interpretation of Visual Inspection Results: Characteristics such as mold marks, ribs, handles, and flutes are often indicative of a pressed rather than blown glass article.

3.1.2 Dimensional Measurement (Applies Only to Stemware, Tumblers, Bowls, etc.):

Using a caliper or similar device, measure the minimum diameter of the mouth, opening, or upper rim of the sample. With the same device, measure the maximum inside diameter. Record both measurements.

Interpretation of Dimensional Measurement Results: A sample having a maximum inside diameter greater than the minimum diameter of the mouth, opening, or upper rim is not likely to have been “pressed.”

Interpretation of the Macroscopic Analysis Test: The analyst is advised to consider the overall features of the article and the dimensional analysis test results in determining that an article has been “pressed.” If the results show that the sample is not “pressed”, the testing sequence for this sample should be terminated at this point.

Evaluation for Determination if an Article Has Been Toughened (Specially Tempered)

3.2 Thermal Shock Test:

• Heat the sample(s) in an oven to 160 °C for 30 minutes.
• Remove one sample from the oven and immediately immerse it in a water bath set at 25 °C. This results in a 135 °C difference in temperature. [Note: Reasonable alternate oven and water bath settings up to ± 10 °C are acceptable as long as the 135 °C difference in temperature is maintained.]

Interpretation of Thermal Shock Test Results: Annealed glassware and inadequately or partially tempered glassware will generally not survive this test of durability or toughness. If breakage occurs, the sample is not “toughened” for CBP purposes. Record the findings, and terminate the analysis.

3.3 Evaluation of Temper:

3.3.1 The Polariscopic Examination (For Transparent or Translucent Articles):

This method for the qualitative evaluation of temper in glassware should be conducted only on transparent or translucent articles. This method is not applicable to opaque items or to articles which have been tempered by a process other than thermal tempering. In addition, some translucent articles will not transmit enough polarized light to permit the observation of stress patterns; these items should be evaluated for temper using the Cutting Test.

• Place the full-wave retardation plate (tint plate) between the polarizer and the analyzer. The polarized light must pass through both the sample and the retardation plate for the color-enhanced polariscopic pattern to be observed through the analyzer. Position the retardation plate in direct contact with the polarizer or, alternatively, just in front of the analyzer.
• Turn on the light source.
• Evaluate the stress in the bottom of the intact article by placing its bottom surface in contact with the polarizer so that the polarized light passes perpendicularly through the bottom surface, or as close to perpendicularly as possible, depending upon the article's shape. [This positioning does not work well with stemware because of color patterns caused by the stem itself. With these items, it will be necessary to hold the glass at a slight angle to view the base and the bowl separately.]
• Evaluate the stress in the sides of the intact article, especially near the rim or edge, by positioning the article so that the polarized light passes perpendicularly through the sides near the rim, or as close to perpendicularly as possible, depending upon the article's shape. Observation of the stress patterns in the sidewall and rim areas should be made while viewing through a single thickness of glass. For some items, especially stemware, tumblers, and mugs, this will require holding the article at a slight angle to the polarizer (open end raised slightly).

Interpretation of the Polariscopic Examination: Thermal tempering of glassware involves heating to the softening point followed by rapid cooling. The surfaces cool first and reach a temperature where they become rigid. With further cooling, the interior or core tries to shrink but is prevented from doing so by the rigid surface layers. This results in the surfaces being locked into a state of high compression and the interior locked into compensating tension.

When polarized light travels through a stressed material, they divide into slow and fast fronts. As a result of the difference in speed of the slow and fast rays, interferences occur and a pattern of colors is observed. These colors can be used to evaluate the stresses in the article. As the stress increases, the observed color changes to reflect the amount of stress. The color changes follow a rigorous sequence as the stress-induced retardation, or distance between the fast and slow rays, increases. In low-stress areas, black and shades of gray are seen. Evaluation of low stress is simplified by using a color-enhancing retardation or tint plate which adds a shift of one fringe order, or 565 nm, in the color pattern throughout the observed field. With the tint plate in place, even low and moderately stressed areas will exhibit a contrasting color effect.

Annealed glassware will exhibit a uniform coloration of the polarized light passing through it; there will be essentially no change from the background. Tempered articles will exhibit non-uniform coloration of the polarized light on the bottom surface and sidewalls and bands of color parallel to the rim or lip. [Note: With highly colored articles, it may be helpful to conduct the polariscopic exam without the tint plate. There will be no color enhancement, but the gray to black interference patterns should be readily discernible in tempered articles.]

If the sample passes the Thermal Shock Test and shows evidence of full-surface tempering (as opposed to rim-tempering or partial tempering) when examined polariscopically, the sample has been “toughened (specially tempered)” for CBP purposes.

3.3.2 The Cutting Test for Opaque Glassware

This test is applicable to opaque articles and to those translucent articles which cannot be examined polariscopically because of inadequate transmission of the polarized light.

• Ensure that the saw is equipped with a continuous rim diamond blade designed for wet cutting glass.
• Adjust the cutting head of the saw vertically and horizontally, as necessary, to accommodate the glassware article.
• Be sure the water supply to both sides of the diamond-rimmed blade is adequate.
• Turn on the saw.
• While holding or otherwise securing the article to prevent twisting and binding during the cutting, slowly and gently move the article into contact with the blade.
• Proceed with the cutting.
• Note the breakage pattern, number, and relative shape and size of the fragments (indicate this without making an actual count). Photograph the breakage pattern and/or typical fragments, if indicated.

Interpretation of the Cutting Test: Annealed (non-tempered) glassware will readily accept the diamond-rimmed blade and will be cleanly cut in half. Tempered glass, on the other hand, will break into pieces when cut. The broken pieces will need to exhibit some dicing, crazing (gravel remaining tenuously in contact with neighboring pieces) or graveling. “Some” will be considered to be any diced, crazed or graveled fragments yielded by the broken sample that is more than just a fugitive diced, crazed or graveled fragment. The word “gravel” is intended to be synonymous with “diced pieces” and implies the presence of small cubes of roughly equal dimensions on all six sides. The extent of cutting needed to induce breakage may vary from item to item, but in no event will tempered articles be cleanly cut in half by the diamond-rimmed blade.

3.3.3 Center Punch Test

In the event that the Cutting Test is inconclusive (i.e., if the sample breaks into several large pieces when subjected to the cutting test) or if an article is too small (less than 5″ in diameter) to be safely analyzed by the Cutting Test, the analyst has the option to apply the Center Punch Test to the article. The Center Punch Test should be performed as follows:

• Set the sample to be tested on a solid, level surface.
• Place an upended cardboard box over the item to be tested. The box should be of sufficient size so that the entire article is covered. The box should be altered such that there is a hole in the center which is large enough to admit the shank of a center punch.
• Place the pointed end of the center punch, vertically, against the inside center bottom or heel.
• Strike the dull end of the punch with a hammer, using blows of gradually increasing severity, until breakage occurs.
• Note the breakage pattern, number, and relative shape and size of fragments (indicate this without making an actual count). Photograph the breakage pattern and/or typical fragments, if indicated.

Interpretation of Center Punch Test Results: In order to be considered “tempered” for CBP purposes, it is only necessary for the broken sample to exhibit some dicing, crazing or graveling. “Some” will be considered to be any diced, crazed or graveled fragments yielded by the broken sample that are more than just fugitive diced, crazed or graveled fragments. The word “gravel” is intended to be synonymous with “diced pieces” and implies the presence of small cubes of roughly equal dimensions on all six sides.

“Toughened (specially tempered)” glassware will require considerably more force to break than ordinary glassware with the center punch test and, when it breaks, some graveling or crazing will be observed. Neither graveling nor crazing will be observed in ordinary glassware.

Powder and splinters will occasionally be observed in samples of “toughened (specially tempered)” glassware. Also, few, if any, of these samples will be reduced entirely to gravel; larger fragments will remain. However, these large fragments will seldom be exceptionally pointed or jagged and broken edges, especially on diced pieces, will be reasonably dull.

The stem and base of the stemware styles seldom disintegrate. The most common breakage pattern for stemware is characterized by a tack-shaped fragment consisting of the base and a portion of the stem remaining intact. The tip of the stem portion should be reasonably dull.

A sample that passes the Thermal Shock Test and shows evidence of tempering per the guidance given above for the Cutting Test and/or Center Punch Test has been “toughened (specially tempered)” for CBP's tariff classification purposes.

Dated: September 9, 2010.

Ira S. Reese,

Executive Director, Laboratories and Scientific Services, U.S. Customs and Border Protection.