1、b .“39 -* A-A-54272 b5 W 9777774 0057569 5 W A-A-54292 30 November 1990 COMMERCIAL ITEM DESCRIPTION BURS, DENTAL EXCAVATING (Tungsten Carbide) The General Services Administration has authorized the use of this Commercial Item Description as a replacement for Federal Specification GG-B-821 and Interi
2、m Federal Specification GG-B-00821E which are cancelled. Salient Characteristics: This commercial item description covers excavating burs suitable for use in dental cavity preparations. Except as noted below, the burs shall be in accordance with the latest issue of ANSI (American National Standards
3、Institute)/ADA (American Dental Association) Specification No. 23. In case of a conflict, this document shall govern. Tvpes. Dental burs covered by this description shall be type II (carbide) burs. Classes. In addition to those bur classes covered in ADA Specification No. 23 the following class will
4、 be covered by this document: Class 2a - Straight handpiece - J-notched Material. Tunqsten carbide. The burs shall be of two-piece construction. The head shall be fabricated from one solid piece of cemented tungsten carbide with cobalt binder. Steel. The one-piece shank, neck and bur head base shall
5、 be fabricated from hardened and properly tempered AISI-S5 tool steel, or as an alternate, martensitic corrosion resisting steel type 420C in accordance with ASTM designation F899 with a minimum Rockwell hardness of C45. The filler metal used in joining carbide to corrosion resistant steel shall con
6、tain a minimum of 47% silver and shall have a melting range of 1290OF to 1590OF. Rockwell hardness shall be tested as specified in ASTM designation E18. AMSC N/A FSC 6520 PISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. o Provided by IHSNot for ResaleNo reproduction
7、or networking permitted without license from IHS-,-,-A-A-5 4292 Dimensions. Dimensions for burs not covered in ADA Specification No. 23 shall be as shown in Table 1 of this description. Shank dimensions for class 2a burs shall be in accordance with Figure 1 of this description. Class la, lb, 2 and 2
8、a shanks may have flat ends provided the edges are rounded . Design and construction. The burs shall be suitable for use in the cavity preparation of natural dentition. The bur shall consist of a shank, a neck and a head. The joint between the head and neck shall be smoothly machined so that the res
9、ultant shape has the appearance of an integral head unit. Increase in runout. The increase in runout shall be no greater than 0.003 inch when determined only on those samples which have been subjected to the neck strength test, and shall be performed in the manner specified for runout. The differenc
10、e between the final and the initial runout shall be taken as the increase in runout. Cuttins ability. The maximum total time for cutting a brass sheet horizontally shall be as specified in Table 2 of this description for the applicable bur size number, when tested as specified herein. Durability. Th
11、e minimum total depth of 25 holes shall be as specified in Table 3 of this description for the applicable bur size number, when tested as specified herein. Autoclavinq. The entire surface area of the non-carbide portion of the bur shall be examined for evidence of corrosion after the bur is cleaned
12、in accordance with the instructions supplied by the manufacturer and autoclaved at 270 2 5OF and 27 2 1 psi pressure for a minimum of 20 minutes. Corrosion present at the welded joint shall be disregarded, and shall not be cause for rejection. Finish. The bur head shall have a finely honed finish wi
13、th sharpened blades. The neck and shank of burs shall be smoothly finished. The tool steel portion of burs, when applicable shall be chromium or nickel plated. A flash gold plating shall be optional on No. 1931 and No. 1958 burs. Latch type and J-notched burs shall have latch and J-notched ends clea
14、nly finished and free of burrs and slivers. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-54272 b5 9779974 0057573 3 A-8-54292 Table 1. Head and neck dimensions I t I I I I I Head 1 ITAPER/CONE I Neck I ! CARBIDE ! ANGLE f I MIN I ! LENGTH I
15、(TOTAL I NECK USA I NO. I DIAMETER ! MINIMUM IBOTH SIDES) !DIAMETER SIZE !BLADES! TYPE II I TYPE II !MAXIMUM I I I I IN. I TOL. I IN. I DEGREES t IN. 1/4 1691; 245 271 1/2P 329 330L a 699 703l- 1157 1931 Round-plain blade - 6 0.019 0.003 o. 012 Tapered fissure, long-plain blade, flat end 6 O. 035 O.
16、 003 0.193 4-8 Amalgam preparation 6 0.035 O. 003 0.107 1-3 Inlay preparation 6 O. 047 O. 003 O. 105 4-8 Pear shape-plain blade 6 O. 024 O. 003 O. 016 - 6 O. 024 0.003 O. 059 4-8 Pear shape, long-plain blade 6 O. 031 0.003 0.110 4-8 Tapered fissure-crosscut blade, flat end 6 O. 035 O. 003 O. 126 4-8
17、 6 O. 083 O. 003 0.177 4-8 Straight fissure-plain blade, dome 6 O. 039 O. 003 0.146 0-2 Pear-fine crosscut 6 0.039 O. 003 0.059 2-4 O. 016 0.035 0.033 O. 048 o. o19 o. o19 O. 027 0.035 O . 067 O. 035 O. 030 Straight fissure-fine crosscut, dome 1958 6 O. 047 O. 003 0.146 0-2 O. 047 The distal head di
18、ameter of the 703 bur shall be 0.058 2 0.002 inch. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-54272 b5 W 7777774 0057572 5 W . *+ A-A-5 42 92 Table 2. Cuttinq abilitv requirements. I I I l I I I 1/4 1/2 1/2P 2 4 4s 6 8 33-1/2 34 35 35s 37
19、39 56 57 168 169L 170L 545 271 329 330 330L 331L 5565 ! THICKNESS OF I DEPTH OF ! PROJECTION OF IMAXIMUM TOTAL USA I BRASS SHEET !SETTING FOR :BUR TIP THROUGHICUTTING TIME I I I I I I I l I I SIZE I I CUT I SHEET I I IN I INOZ- I IN. SECONDS o . o11 O. 015 O. 004 40 I o. o11 o. o11 o. o11 o . 020 o.
20、 020 o. 020 o . 020 o e o11 o . o11 o. o11 o. o11 0.020 0.020 0.020 0.020 o . o11 0.020 o. 020 o. o11 0.020 o. o11 o . o11 o . o11 o. 020 0.020 O . 015 O. 015 o. 022 O. 034 O. 034 0.042 O . 052 O. 016 O. 016 0.016 O . 016 O. 025 0.025 O. 060 O. 060 O . 051 O. 060 0.060 O. 016 0.060 O. 016 O . 016 O.
21、 016 O. 060 0.060 O . 004 O. 004 o o11 O . 014 O. 014 0.022 O 032 O. 005 O 005 O. 005 O. 005 O . 005 O. 005 O. 040 O. 040 O. 040 O . 040 O. 005 O . 040 O. 005 O 005 O. 005 O. 040 O. 040 O 040 40 40 25 25 25 25 25 25 25 25 25 50 50 50 wet3 - 50 50 50 wet3 - 50 wet3 - 25 50 25 25 25 50 50 2- The “Dept
22、h of setting for cut“ indicates the depth of the bur tip below the top surface of the brass sheet. The difference between this depth and the “Thickness of brass sheet“ is the “Projection of the bur tip through sheet“ (distance from the bottom surface of the brass sheet downward to the tip of the bur
23、) 3= A lubricant or other suitable cutting fluid shall be used for the cutting test on the 56, 169L and 170L burs only. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- A-A-54272 b5 7777774 0057573 7 +Y . A-A-5 4 2 92 Table 2. Cuttinq abilitv requi
24、rements (continued). 8. I I I I I I I I I THICKNESS OF I DEPTH OF PROJECTION OF !MAXIMUM TOTAL USA I BRASS SHEET !SETTING FOR IBUR TIP THROUGHICUTTING TIME I l I I l I l CUT I SHEET I l IN. I IN.2- I IN. I SECONDS SIZE I I I I I 1 I I I 557 o. 020 O. 060 O. 040 50 558 o. 020 O. 060 O. 040 50 558s o.
25、 020 O. 060 O. 040 50 559 o. 020 0.060 O. 040 50 699 o. o11 O. 051 O. 040 50 700 0.020 O. 060 O. 040 50 701 0.020 O. 060 O. 040 50 702 0.020 0.060 O. 040 50 703 o. 020 0.060 O 040 50 957 (Tests not applicable) 1157 o. 020 O. 060 O. 040 50 1931 o. Oil O. 016 0.005 25 1958 0.020 O. 060 O. 040 50 Table
26、 3. Durabilitv requirements. 0 I l I I I I I MINIMUM TOTAL DEPTH I OF 25 HOLES, INCH USA BUR SIZE NUMBER 1/4 0.200 1/2 O. 240 1/2P O. 240 2 O. 400 4 O. 400 4s O. 400 6 0.400 8 O. 400 33-1/2 O. 240 34 O. 240 35 O. 300 35s O. 300 37 O. 400 39 O. 400 56 O. 325 57 O. 400 5 Provided by IHSNot for ResaleN
27、o reproduction or networking permitted without license from IHS-,-,-A-A-54292 b5 W 7999974 0057574 9 H A-A-54292 Table 3. Durability requirements (continued) . I l l I I l USA I MINIMUM TOTAL DEPTH BUR SIZE NUMBER 1. OF 25 HOLES, INCH 168 O. 300 169L O. 300 170L O. 325 245 O. 300 271 O. 400 329 O. 3
28、00 330 O. 300 330L O. 300 331L O. 300 556s O. 325 557 0.400 558 0.400 5588 0.400 559 O. 400 699 O. 300 700 O. 300 701 0.400 702 0.400 703 0.400 957 (Tests not applicable) 1157 O. 400 1931 0.300 1958 0.400 Markinq. Marking of burs shall be optional. The use of a trademark is optional. the marking sha
29、ll not adversely affect or interfere with the handpiece. Markings shall be distinguishable to the unaided eye. The type of marking or placement of Instructions. Adequate and accurate instructions shall be furnished with each unit of issue on the use and care of the burs. Instructions shall also incl
30、ude the type of solutions, both suitable and unsuitable for cold sanitation of the burs. Workmanship. The burs shall have uniformly cut and formed blades and shall be free from defects which detract from their appearance or may impair their intended use. 6 Provided by IHSNot for ResaleNo reproductio
31、n or networking permitted without license from IHS-,-,-*i A-A-5q292 b5 W 7799974 O057575 O W A-A- 5 4 2 9 2 - Unit. Package (PG). One package containing 10 individually separated burs of one type, class and size only, as specified, constitutes one unit. Qualitv Assurance Provisions. General. Quality
32、 assurance provisions shall be as specified in this document. Sections 4.1 through 4.1.2 of ADA Specification No. 23 shall not apply. Responsibilitv for inspection. Unless otherwise specified in the contract or purchase order, the contractor is responsible for the performance of all inspection requi
33、rements as specified herein. Except as otherwise specified in the contract or purchase order, the contractor may use his own or any facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. The Government reserves the right to perf
34、orm any of the inspections set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. Records. Records of examinations and tests performed by or for the contractor shall be maintained by the contractor and made avail
35、able to the Government upon the Governments request, at any time, or from time to time, during the performance of the contract and for a period of three years after the delivery of the supplies to which such records relate. 0 Inspection. Inspection, as used herein, is defined as both examination (su
36、ch as visual or auditory investigation without the use of special laboratory appliances or procedures) and testing (determination by technical means of physical and chemical properties) of the item. Samplinq for examination. Sampling for examination shall be conducted in accordance with MIL-STD-105,
37、 with an inspection level of II and AQL (Percent defective) of 2.5. The unit of product for examination purposes shall be one bur. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-5q272 65 m 9999774 0057576 2 m L A-A-5 42 92 Examination. Examina
38、tion shall be as specified herein. Examination shall include, but shall not be limited to the following: Defects Bur size number or head shape not as specified. Bur shank (class) not as specified. Cut off end on shank not as shown in applicable figure. Burs not free from defects such as chipped blad
39、es, Number of blades not as specified for the applicable Finish on bur not as specified. instructions for use inaccurate, inadequate or missing. Welded joint of bur does not give the appearance of an Packaging not as specified. cracks or pits. bur size number. integral head unit. Samplins for .tests
40、. Sampling for tests shall be conducted in accordance with MIL-STD-105 and as specified below. The acceptance number shall be zero for all sample sizes. The unit of product for test purposes shall be as specified below. Test Criteria Test inspection Unit of Characteristics Requirement procedure 1 ev
41、e 1 product Hardness Dimensions Runout Surface roughness Neck strength Increase in Cutting ability Durability Autoclaving runout Herein ADA No. 23 ADA No. 23 ADA No. 23 ADA No. 23 Herein Herein Herein Herein Herein ADA No. 23 ADA No. 23 ADA No. 23 ADA NO. 23 Herein Herein Herein Herein s-1 s-1 s-3 s
42、-1 s-3 s-3 s-1 s-1 s-1 1 bur 1 bur 1 bur 1 bur 1 (class 4 bur) 1 bur 5 burs 5 burs 1 bur Tests. Tests shall be conducted to determine compliance with specification requirements. Tests not specified in this document shall be performed in accordance with the procedures specified in ADA Specification N
43、o. 23 or as otherwise specified. Where feasible, the same sample shall be used for the determination of two or more test characteristics. 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-54272 65 m 7777774 0057577 m A-A-5 4 2 92 Cuttins abilitv.
44、 Test material. The test material shall be cartridge brass sheet conforming to copper alloy no. C26000 of ASTM designation B36. The sheet shall have a Rockwell hardness of 340 to B65 and shall have a thickness of 0.011 inch (24 gage Brown and Sharpe) or 0.020 inch (29 gage B & SI, as specified in Ta
45、ble 2 of this description. The sheet shall be cut into strips of suitable size for use in the test equipment as specified below. Equipment for tests. The equipment shall consist of a precision chuck capable of holding the burs to be tested, a movable carriage for the test material, and the necessary
46、 accessories for measuring within 0.5 second the time required for the bur to cut 0.020 inch. The equipment shall be capable of applying a constant one-pound contact load between the bur and the test strip perpendicular to the bur axis. Test procedure. A test bur and a brass sheet of the proper thic
47、kness shall be placed in the test equipment. The bur shall be positioned perpendicular to the brass strip and the relative heights adjusted as specified in Table 2 of this description. The bur shall be rotated at a speed of 4350 2 50 revolutions per minute (rpms) and brought into contact with the ed
48、ge of the brass strip. A preliminary cut equal to one-half to one bur diameter shall be made before readings are taken. The time required for the bur to cut horizontally a distance of 0.020 inch into the sheet shall be determined to 2 0.5 second. The test shall be repeated until a total of 5 burs ha
49、ve been tested. Durability. Test material. The test material shall be a crystal plate glass, a minimum of 1/8 inch thick, having a Knoop hardness of 450 to 510 with a one kilogram load. Equipment for test. The equipment shall consist of a true-running chuck capable of holding and rotating the bur being tested, and a movable platform or carriage suitable for carrying the flat surface of a glass test block into contact wit
