MS21250 : Mil-Spec Hardware
MS21250 : Mil-Spec Hardware Specification
Bolt, Tension, Steel, External Wrenching, Flanged, 12-Point, 180 KSI Ftu, 450°F
Click on drawing for larger view
1. MATERIAL: Steel alloy, MIL-S-5626 (AISI 4140) MIL-5-5000 (AISI 4340) MIL-S-6049 (AISI 8740) MIL-S-8503 (AISI 6150).
2. PLATING: Cadmium plate in accordance with QQ-P-416, Type II, Class 2. Class 3 may be used until 1 Jan 1974.
3. SURFACE TEXTURE: In accordance with ANSI (ASA) B46.1. Unless otherwise specified, the surface texture shall not exceed 125 microinches.
4. Dimensions are in inches, unless otherwise specified. Tulerances: Decimals +-.010, Angles +-2°.
5. Dimensions to be met after plating.
6. Tensile strength to be 180,000 to 200,000 psi.
7. Diameter Dash No. at top of Table, Sheet 3, plus grip Dash No. first column on left of Table constitute a complete dash No., identifying specified lengths of a given size of bolt. Grip equals last three dash numbers times .0625.
8. And letter H before Dash No. to designate drilled head, first two dash numbers designate diameter in sixteenths. Last three dash numbers designate grip length in sixteenths. Unassigned intermediate or longer grip lengths not included in Table may be specified by the use of whole dash numbers only.
- Examples of preferred part number:
- MS21250-04008 = bolt, undrilled head, .2500-28, .50 grip length
- MS21250H04008 = bolt, drilled head, .2500-28, .500 grip length
- Examples of unassigned part number:
- MS21250-04009 = bolt, undrilled head, .2500-28, .562 grip length
- MS21250H04009 = bolt, drilled head, .2500-28, .562 grip length
.2500 Diameter of thread
28 Threads per inch
See Table on Sheet 3 for preferred grip dash numbers.
Grip length of bolt shall be measured from underside of head to the end of full cylindrical portion of the shank
9. HARDNESS: 39-43 HRC.
For design feature purposes, this standard takes precedence over procurement documents referenced herein. Referenced documents shall be of the issue in effect on date of invitations for bid.
L – Inactive for new design after 4 Dec 1990.
Need the Spec?
Click here to download MS21250 Specification