AN960 Flat Washer Part Number Decoder: Coating, Material, Dash Number and Thickness Codes

What Does AN960C416L Mean?

Type any AN960 part number below. The decoder splits it into coating code, material code, dash number and thickness letters, checks it against the AN960 sheet, and gives the NAS1149 washer that replaces it. Spaces, dashes and lower case are fine.

AN960 has been inactive for new design since 1992; NAS1149 replaces it part for part. Use the NAS1149 decoder for the replacement number, or the Washer Size Finder to identify a washer by measuring it.

AN960 DECODER
coating · material · size · thickness AN960 Rev 21, Aug 1992
Examples:
Part numberSizeThk inID inOD inMaterial, coatingNAS1149 substitute
How an AN960 Part Number Is Built
AN960 standard X coating: black oxide C material: CRES 616 dash number: 3/8 in bolt LL thickness: extra light, .016 in

This is the sheet's own example (Note 10). Coating and material letters are left out when there is no code: carbon steel is AN960-616, passivated CRES is AN960C616.

Coating and Material Codes
LettersMaterialCoatingNote
(none), written AN960-Carbon steelCadmium plate (no code)
CCorrosion-resistant steelPassivated (no code)Uncoated CRES is passivated
XCCorrosion-resistant steelBlack oxideX is for CRES only
JDAluminum 2024Chemical surface treatmentLow electrical resistance (Note 5)
KDAluminum 2024AnodizeCorrosion protection (Note 6)
PDAluminum 2024Anodize or chem filmInactive; use J or K (Note 7)
DAluminum 2024Untreated (no code)
BBrassNatural (no code)Inactive for new design (Note 8)
Every AN960 Number by Size and Column
SizeID / OD, inCarbon steel (-)CRES (C)CRES black (XC)Al chem (JD)Al anodize (KD)Al P (PD)Al bare (D)Brass (B)
No. 20.099 / 0.2502L .016
2 .032		2L .016
2 .032		2L .016
2 .032		2L .016
2 .032		2L .016
2 .032		2L .016
2 .032		2L .016
2 .032		2 .032
No. 30.105 / 0.2503L .016
3 .032		3L .016
3 .032		3L .016
3 .032		3L .016
3 .032		3L .016
3 .032		3L .016
3 .032		3L .016
3 .032		3 .032
No. 40.125 / 0.3124L .016
4 .032		4L .016
4 .032		4L .016
4 .032		4L .016
4 .032		4L .016
4 .032		4L .016
4 .032		4L .016
4 .032		4 .032
No. 50.140 / 0.4385 .0425 .0425 .0425 .0425 .0425 .0425 .0425 .042
No. 60.149 / 0.3756L .016
6 .032		6L .016
6 .032		6L .016
6 .032		6L .016
6 .032		6L .016
6 .032		6L .016
6 .032		6L .016
6 .032		6 .032
No. 80.174 / 0.3758L .016
8 .032		8L .016
8 .032		8L .016
8 .032		8L .016
8 .032		8L .016
8 .032		8L .016
8 .032		8L .016
8 .032		8 .032
No. 90.188 / 0.5009 .0499 .0499 .0499 .0499 .0499 .0499 .0499 .049
No. 100.203 / 0.43810L .032
10 .063		10L .032
10 .063		10LL .016
10L .032
10 .063		10LL .016
10L .032
10 .063		10LL .016
10L .032
10 .063		10L .016
10 .063		10L .016
10 .063		10 .063
No. 110.234 / 0.62511 .06511 .06511 .06511 .06511 .06511 .06511 .06511 .065
1/40.265 / 0.500416L .032
416 .063		416L .032
416 .063		416L .032
416 .063		416L .016
416 .063		416L .016
416 .063		416L .016
416 .063		416L .016
416 .063		416 .063
5/160.328 / 0.562516L .032
516 .063		516L .032
516 .063		516L .032
516 .063		516L .016
516 .063		516L .016
516 .063		516L .016
516 .063		516L .016
516 .063		516 .063
3/80.390 / 0.625616LL .016
616L .032
616 .063		616LL .016
616L .032
616 .063		616LL .016
616L .032
616 .063		616L .016
616 .063		616L .016
616 .063		616L .016
616 .063		616L .016
616 .063		616 .063
7/160.453 / 0.750716L .032
716 .063		716L .032
716 .063		716LL .016
716L .032
716 .063		716L .016
716 .063		716L .016
716 .063		716L .016
716 .063		716L .016
716 .063		716 .063
1/20.515 / 0.875816L .032
816 .063		816L .032
816 .063		816L .032
816 .063		816L .016
816 .063		816L .016
816 .063		816L .016
816 .063		816L .016
816 .063		816 .063
9/160.578 / 1.062916L .032
916 .063		916L .032
916 .063		916L .032
916 .063		916L .016
916 .063		916L .016
916 .063		916L .016
916 .063		916L .016
916 .063		916 .063
5/80.640 / 1.1881016L .032
1016 .063		1016L .032
1016 .063		1016L .032
1016 .063		1016L .016
1016 .063		1016L .016
1016 .063		1016L .016
1016 .063		1016L .016
1016 .063		1016 .063
3/40.765 / 1.3121216L .032
1216 .090		1216L .032
1216 .090		1216L .032
1216 .090		1216L .016
1216 .090		1216L .016
1216 .090		1216L .016
1216 .090		1216L .016
1216 .090		1216 .090
7/80.890 / 1.5001416L .032
1416 .090		1416L .032
1416 .090		1416L .032
1416 .090		1416L .016
1416 .090		1416L .016
1416 .090		1416L .016
1416 .090		1416L .016
1416 .090		1416 .090
11.015 / 1.7501616L .032
1616 .090		1616L .032
1616 .090		1616L .032
1616 .090		1616L .016
1616 .090		1616L .016
1616 .090		1616L .016
1616 .090		1616L .016
1616 .090		1616 .090
1-1/161.078 / 1.8121716L .032
1716 .090		1716 .0901716 .0901716L .016
1716 .090		1716L .016
1716 .090		1716L .016
1716 .090		1716L .016
1716 .090		1716 .090
1-1/81.140 / 1.8751816L .032
1816 .090		1816 .0901816 .0901816L .016
1816 .090		1816L .016
1816 .090		1816L .016
1816 .090		1816L .016
1816 .090		1816 .090
1-1/41.265 / 2.0002016L .032
2016 .090		2016 .0902016 .0902016L .016
2016 .090		2016L .016
2016 .090		2016L .016
2016 .090		2016L .016
2016 .090		2016 .090
1-5/161.328 / 2.0622116L .032
2116 .090		2116 .0902116 .0902116L .016
2116 .090		2116L .016
2116 .090		2116L .016
2116 .090		2116L .016
2116 .090		2116 .090
1-5/81.640 / 2.3752616L .032
2616 .090		2616 .0902616 .0902616L .016
2616 .090		2616L .016
2616 .090		2616L .016
2616 .090		2616L .016
2616 .090		2616 .090
1-7/81.890 / 2.6253016L .032
3016 .090		3016 .0903016 .0903016L .016
3016 .090		3016L .016
3016 .090		3016L .016
3016 .090		3016L .016
3016 .090		3016 .090
2-1/42.265 / 3.0003616L .032
3616 .090		3616 .0903616 .0903616L .016
3616 .090		3616L .016
3616 .090		3616L .016
3616 .090		3616L .016
3616 .090		3616 .090
2-1/22.515 / 3.2504016L .032
4016 .090		4016 .0904016 .0904016L .016
4016 .090		4016L .016
4016 .090		4016L .016
4016 .090		4016L .016
4016 .090		4016 .090

Each cell lists the dash number with its thickness letters and the thickness in inches. ID ±.010, OD +.020/−.005 in. Thickness ±.010 in, except aluminum: .016 ±.003, .032 ±.004, .042 ±.004, .049 ±.005, .063 ±.006, .090 ±.007 (Note 2).

Reference Guide: Reading AN960
01

The Rules of the Code

Order of the parts
  1. Coating code (if any): X, J, K or P.
  2. Material code (if any): C, D or B. No letter means carbon steel.
  3. Dash number: the bolt or screw size.
  4. Thickness code: none (regular), L (light) or LL (extra light).

Carbon steel numbers have a dash because there are no letters: AN960-416. All others run together: AN960C416, AN960KD416L.

Dash numbers
  • Screw sizes: the screw number, 2 to 11. AN960-4 fits a No. 4 screw, not a 1/4 in bolt.
  • Bolt sizes: the size in sixteenths followed by 16: 416 = 4/16 = 1/4 in, 616 = 3/8, 816 = 1/2, 1216 = 3/4, 1616 = 1 in, 4016 = 2-1/2 in.
  • The medium series (M) was cancelled after 20 July 1984 (Note 11).
02

L and LL Change Meaning by Column

The thickness letters do not stand for one thickness. They pick the thinner of the washers listed for that size in that column. The thickness depends on the material and coating:

Part numberThickness
AN960-416 / AN960-416L.063 / .032
AN960JD416 / AN960JD416L.063 / .016
AN960XC10 / 10L / 10LL.063 / .032 / .016
AN960-1216 / AN960-1216L.090 / .032

So AN960C416L (CRES) is .032 thick, but AN960JD416L (aluminum) is .016 thick. Always read the thickness from the table, not the letter.

The decoder takes every thickness from NAS1149 Table IV, which lists a NAS1149 substitute of a stated thickness for each AN960 number.
03

"No Code" Means Different Things

AN960 leaves the coating letter off for the most common finish of each material. A number with no coating letter is still coated or treated:

  • Carbon steel (AN960-416): cadmium plated.
  • CRES (AN960C416): passivated. Stainless needs no coating letter on AN960.
  • Aluminum (AN960D416): untreated, bare 2024.
  • Brass (AN960B416): natural brass.
NAS1149 does it differently

NAS1149 always ends with a finish letter. Passivated CRES there is R: AN960C416L becomes NAS1149C0432R. Untreated aluminum is H (none). Black oxide is B on NAS1149 but X on AN960.

04

Status and Replacement

AN960 Revision 21 (6 August 1992) is marked "inactive for new design. NAS 1149 may be substituted in all applications." Existing stock may be used until depleted.

  • Brass and P-coated washers were reinstated from "cancelled" to "inactive for new design" (Notes 7 and 8).
  • No. 2 sizes: inactive for new design (Note 9).

Every AN960 number has a NAS1149 substitute in NAS1149 Table IV. P-coated aluminum (PD) maps to two: one with J (chem film) and one with K (anodize).

Sources: AN960 Revision 21 (6 Aug 1992), sheets 1 to 3, and NAS1149 Revision 4 (Feb 2008) Table IV.

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