Specification
Where to buy| Item | Value |
|---|---|
| Head | pan, cross-recessed |
| Drive | cross-recess (MS9006) |
| Thread series | UNC-2A |
| Material | Aluminum alloy 2024, QQ-A-200/3 or QQ-A-225/6; minimum ultimate tensile strength 62000 psi |
| Item | Value |
|---|---|
| Finish | Anodized, MIL-A-8625, Type I or II, Class 1 |
| Procurement | FF-S-92 |
| Thread specification | FED-STD-H28/2 |
| Status | Check the current issue before design use. Rev. B (12 Jun 1974). Amendment 1 (5 Oct 1992): P head radius changed from minimum to reference; threads per FED-STD-H28/2, acceptability per FED-STD-H28/20, System 21. Notice 1 (18 Nov 1999): Inactive for new design; used only for replacement purposes. Notice 2 (Sep 2018): remains inactive for new design; valid for use. Notice 3 (Mar 2025): remains inactive for new design; valid for use. |
Dimensions by size
| Dimension, in | .086-56 UNC-2A | .112-40 UNC-2A | .138-32 UNC-2A | .164-32 UNC-2A | .190-24 UNC-2A | .250-20 UNC-2A | .3125-18 UNC-2A | .375-16 UNC-2A |
|---|---|---|---|---|---|---|---|---|
| D body dia | .0717 – .0860 | .0925 – .1120 | .1141 – .1380 | .1399 – .1640 | .1586 – .1900 | .2127 – .2500 | .2712 – .3125 | .3287 – .3750 |
| A head dia | .155 – .167 | .205 – .219 | .256 – .270 | .306 – .322 | .357 – .373 | .473 – .492 | .594 – .615 | .716 – .740 |
| H head height | .053 – .062 | .070 – .080 | .087 – .097 | .105 – .115 | .122 – .133 | .162 – .175 | .203 – .218 | .244 – .261 |
| P head radius ref | .010 | .010 | .015 | .015 | .020 | .035 | .040 | .040 |
| R fillet radius max | .013 | .017 | .021 | .025 | .029 | .038 | .047 | .056 |
| driver size | 1 | 1 | 2 | 2 | 2 | 3 | 4 | 4 |
| min tensile lbf | 225 | 370 | 560 | 860 | 1080 | 1970 | 3250 | 4800 |
Inches, minimum - maximum as tabulated in MS35218 Rev. B; letters as on the standard's drawing. P is a reference value (Amendment 1).
Part numbers and lengths
Every part number of MS35218 by size and length L, as Table I assigns them.
.086-56 UNC-2A9 part numbers · tolerance +.00/-.03
| Part no. | Length, in |
|---|---|
| MS35218-1 | .12 |
| MS35218-2 | .19 |
| MS35218-3 | .25 |
| MS35218-4 | .31 |
| MS35218-5 | .38 |
| MS35218-6 | .44 |
| MS35218-7 | .50 |
| MS35218-8 | .62 |
| MS35218-9 | .75 |
.112-40 UNC-2A11 part numbers · tolerance +.00/-.03
| Part no. | Length, in |
|---|---|
| MS35218-10 | .12 |
| MS35218-11 | .19 |
| MS35218-12 | .25 |
| MS35218-13 | .31 |
| MS35218-14 | .38 |
| MS35218-15 | .44 |
| MS35218-16 | .50 |
| MS35218-17 | .62 |
| MS35218-18 | .75 |
| MS35218-19 | .88 |
| MS35218-20 | 1.00 |
.138-32 UNC-2A15 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-21 | .12 | +.00/-.03 |
| MS35218-22 | .19 | +.00/-.03 |
| MS35218-23 | .25 | +.00/-.03 |
| MS35218-24 | .31 | +.00/-.03 |
| MS35218-25 | .38 | +.00/-.03 |
| MS35218-26 | .44 | +.00/-.03 |
| MS35218-27 | .50 | +.00/-.03 |
| MS35218-28 | .62 | +.00/-.03 |
| MS35218-29 | .75 | +.00/-.03 |
| MS35218-30 | .88 | +.00/-.03 |
| MS35218-31 | 1.00 | +.00/-.03 |
| MS35218-32 | 1.25 | +.00/-.06 |
| MS35218-33 | 1.50 | +.00/-.06 |
| MS35218-34 | 1.75 | +.00/-.06 |
| MS35218-35 | 2.00 | +.00/-.06 |
.164-32 UNC-2A15 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-36 | .12 | +.00/-.03 |
| MS35218-37 | .19 | +.00/-.03 |
| MS35218-38 | .25 | +.00/-.03 |
| MS35218-39 | .31 | +.00/-.03 |
| MS35218-40 | .38 | +.00/-.03 |
| MS35218-41 | .44 | +.00/-.03 |
| MS35218-42 | .50 | +.00/-.03 |
| MS35218-43 | .62 | +.00/-.03 |
| MS35218-44 | .75 | +.00/-.03 |
| MS35218-45 | .88 | +.00/-.03 |
| MS35218-46 | 1.00 | +.00/-.03 |
| MS35218-47 | 1.25 | +.00/-.06 |
| MS35218-48 | 1.50 | +.00/-.06 |
| MS35218-49 | 1.75 | +.00/-.06 |
| MS35218-50 | 2.00 | +.00/-.06 |
.190-24 UNC-2A15 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-51 | .25 | +.00/-.03 |
| MS35218-52 | .31 | +.00/-.03 |
| MS35218-53 | .38 | +.00/-.03 |
| MS35218-54 | .44 | +.00/-.03 |
| MS35218-55 | .50 | +.00/-.03 |
| MS35218-56 | .62 | +.00/-.03 |
| MS35218-57 | .75 | +.00/-.03 |
| MS35218-58 | .88 | +.00/-.03 |
| MS35218-59 | 1.00 | +.00/-.03 |
| MS35218-60 | 1.25 | +.00/-.06 |
| MS35218-61 | 1.50 | +.00/-.06 |
| MS35218-62 | 1.75 | +.00/-.06 |
| MS35218-63 | 2.00 | +.00/-.06 |
| MS35218-64 | 2.25 | +.00/-.09 |
| MS35218-65 | 2.50 | +.00/-.09 |
.250-20 UNC-2A14 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-66 | .31 | +.00/-.03 |
| MS35218-67 | .38 | +.00/-.03 |
| MS35218-68 | .44 | +.00/-.03 |
| MS35218-69 | .50 | +.00/-.03 |
| MS35218-70 | .62 | +.00/-.03 |
| MS35218-71 | .75 | +.00/-.03 |
| MS35218-72 | .88 | +.00/-.03 |
| MS35218-73 | 1.00 | +.00/-.03 |
| MS35218-74 | 1.25 | +.00/-.06 |
| MS35218-75 | 1.50 | +.00/-.06 |
| MS35218-76 | 1.75 | +.00/-.06 |
| MS35218-77 | 2.00 | +.00/-.06 |
| MS35218-78 | 2.25 | +.00/-.09 |
| MS35218-79 | 2.50 | +.00/-.09 |
.3125-18 UNC-2A13 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-80 | .38 | +.00/-.03 |
| MS35218-81 | .44 | +.00/-.03 |
| MS35218-82 | .50 | +.00/-.03 |
| MS35218-83 | .62 | +.00/-.03 |
| MS35218-84 | .75 | +.00/-.03 |
| MS35218-85 | .88 | +.00/-.03 |
| MS35218-86 | 1.00 | +.00/-.03 |
| MS35218-87 | 1.25 | +.00/-.06 |
| MS35218-88 | 1.50 | +.00/-.06 |
| MS35218-89 | 1.75 | +.00/-.06 |
| MS35218-90 | 2.00 | +.00/-.06 |
| MS35218-91 | 2.25 | +.00/-.09 |
| MS35218-92 | 2.50 | +.00/-.09 |
.375-16 UNC-2A13 part numbers
| Part no. | Length, in | Tol. |
|---|---|---|
| MS35218-93 | .50 | +.00/-.03 |
| MS35218-94 | .62 | +.00/-.03 |
| MS35218-95 | .75 | +.00/-.03 |
| MS35218-96 | .88 | +.00/-.03 |
| MS35218-97 | 1.00 | +.00/-.03 |
| MS35218-98 | 1.25 | +.00/-.06 |
| MS35218-99 | 1.50 | +.00/-.06 |
| MS35218-100 | 1.75 | +.00/-.06 |
| MS35218-101 | 2.00 | +.00/-.06 |
| MS35218-102 | 2.25 | +.00/-.09 |
| MS35218-103 | 2.50 | +.00/-.09 |
| MS35218-104 | 2.75 | +.00/-.09 |
| MS35218-105 | 3.00 | +.00/-.09 |
Part number
What each code means
| Part | Meaning |
|---|---|
| Format | MS35218-<dash number> |
| Example | MS35218-1: .086-56 UNC-2A, .12 long |
| Length tolerance, .12 to 1.00 | +.00/-.03 |
| Length tolerance, 1.25 to 2.00 | +.00/-.06 |
| Length tolerance, 2.25 to 3.00 | +.00/-.09 |
| Dash | Dash number from Table I selects size and length (1 to 105) |
Notes from the standard
- Thread length: full form threads extend to within 2 threads or less of the head bearing surface for lengths through 2.00; longer screws have a minimum full form thread length of 1.50.
- Recess in accordance with MS9006. Tensile strength in the table is the minimum, in pounds.
- Supersedes MS35235, MS35313 and, in part, MS35357, MS35359 thru MS35362, MS35364 thru MS35366, AN515 and AN526. Sheets 2 and 3 of the standard list the cancelled dash numbers and the MS35218 numbers that replace them.
- Part number: the MS number plus the dash number, for example MS35218-1.
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Sources
- MS35218 Rev. B, 12 Jun 1974 — Screw, Machine - Pan Head, Cross-Recessed, Aluminum Alloy, UNC-2A — dimensions, part numbers and notes. Public domain, distribution unlimited. Notices: 5 Oct 1992 Amendment 1: P head radius changed from minimum to reference; threads per FED-STD-H28/2, acceptability per FED-STD-H28/20, System 21.; 1 18 Nov 1999 Inactive for new design; used only for replacement purposes.; 2 Sep 2018 Validation: remains inactive for new design; valid for use.; 3 Mar 2025 Validation: remains inactive for new design; valid for use.
Educational reference only. not approved data. Always consult the applicable SRM, AMM, or AC 43.13-1B and your certifying authority.