DLA MS24672 REV B-2006 SCREW CAP SOCKET HEAD FLAT COUNTERSUNK CORROSION RESISTING STEEL UNF-3A《UNF-3A抗腐蚀钢平埋头插座头帽螺丝》.pdf

1、INCH-POUNDMS24672B2 June 2006SUPERSEDING MS24672A 27 March 1961DETAIL SPECIFICATION SHEET SCREW, CAP, SOCKET HEAD, FLAT COUNTERSUNK, CORROSION RESISTING STEEL, UNF-3A Inactive for new design after 27 March 1961 This specification is approved for use by all Departments and Agencies of the Department

2、of Defense. The requirements for acquiring the product described herein shall consist of this specification sheet and FF-S-86. 82 2THEORETICALSHARP MAX.JHARWITH FLAT)A(ABSOLUTE MINIMUMD TSEE NOTE 5 ON SCREWPOINT CHAMFERSEE NOTE 4 ONMINIMUM THREADLENGTHLTREFERENCE MAX.FIGURE 1. Screw TABLE I. Screw D

3、ash Numbers and Dimensions NOMINAL SIZE #10 (.190) .250 .313 .375 .500 THREADS PER INCH 32UNF-3A 28UNF-3A 24UNF-3A 24UNF-3A 20UNF-3A D BODY DIAMETER MAX MIN .190 .1867 .250 .2464 .3125 .3084 .375 .3705 .500 .4948 A HEAD DIAMETER THEO. SHARP MAX ABS. MIN .411 .359 .531 .480 .656 .600 .781 .720 .937 .

4、872 H HEAD HEIGHT REFERENCE MAX .127 .161 .198 .234 .251 J SOCKET WIDTH ACROSS FLATS MAX MIN .1270 .1250 .1582 .1562 .1895 .1875 .2207 .2187 .3155 .3125 T KEY ENGAGEMENT MIN .087 .111 .135 .159 .172 R RADIUS MAX .019 .025 .031 .037 .050 MINIMUM BREAKING STRENGTH LBS. 1400 2550 4060 6150 11200 L LENG

5、TH TOL. DASH NO. DASH NO. DASH NO. DASH NO. DASH NO. .375 .500 .625 .750 1.000 +.016 - .016 1.250 1.500 1.750 2.000 +.031 - .016 1 2 3 4 5 6 7 9 10 11 12 13 14 15 17 18 19 20 21 22 23 25 26 27 28 29 30 32 33 34 35 36 37 AMSC FSC 5305 Provided by IHSNot for ResaleNo reproduction or networking permitt

6、ed without license from IHS-,-,-MS24672B 2 NOTES: 1. MATERIAL: STEEL, CORROSION RESISTANT, IN ACCORDANCE WITH FF-S-86. ULTIMATE LOAD 70,000 PSI MIN TENSILE STRENGTH; PROOF LOAD 30,000 PSI MIN YIELD STRENGTH; ELONGATION 35 PERCENT MIN. 2. PROTECTIVE COATING: PASSIVATED IN ACCORDANCE WITH FF-S-86. 3.

7、THREADS: THE THREADS SHALL BE IN ACCORDANCE WITH FED-STD- H28. 4. MINIMUM THREAD LENGTH: THE MINIMUM USABLE THREAD LENGTH SHALL BE EQUAL TO 2D PLUS .500. THE THREAD LENGTH TOLERANCE SHALL BE EQUAL TO THE NOMINAL DIAMETER. SCREWS TOO SHORT FOR APPLICATION OF THE FORMULA SHALL BE THREADED AS CLOSE TO

8、THE HEAD AS PRACTICABLE. 5. POINT CHAMFER: THE POINTS SHALL BE FLAT AND CHAMFERED. THE FLAT SHALL BE NORMAL TO THE AXIS OF THE SCREW. THE CHAMFER SHALL EXTEND SLIGHTLY BELOW THE ROOT OF THE THREAD AND THE EDGE BETWEEN THE FLAT AND THE CHAMFER MAY BE ROUNDED. THE INCLUDED ANGLE OF THE THREADED POINT

9、SHALL BE APPROXIMATELY 90. CHAMFERING OF SCREW SIZES UP TO AND INCLUDING NO. 8 SHALL BE AT THE OPTION OF THE MANUFACTURER. 6. DIMENSIONS: ALL DIMENSIONS ARE IN INCHES UNLESS OTHERWISE SPECIFIED. 7. PART NUMBER: THE MS PART NUMBER CONSISTS OF THE MS NUMBER, PLUS THE DASH NUMBER. EXAMPLE: MS24672-1 8.

10、 THIS STANDARD TAKES PRECEDENCE OVER DOCUMENTS REFERENCED HEREIN. 9. CHANGES FROM PREVIOUS ISSUE. MARGINAL NOTATIONS ARE NOT USED IN THIS REVISION TO IDENTIFY CHANGES WITH RESPECT TO THE PREVIOUS ISSUE DUE TO THE EXTENT OF THE CHANGES. Custodians: Preparing activity: Navy SH DLA IS Review Activities

11、: (Project 5305-2006-003) Navy AS NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change, you should verify the currency of the information above using the ASSIST Online database at http:/assist.daps.dla.milProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-