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MIL-R-21248B — RING,RETAINING

✓ Government record, cited
— · BOLT SCREW
PRODUCT OVERVIEW

MIL-R-21248B: RING,RETAINING.

The RING,RETAINING is a the manufacturer industrial component. Key specifications include ring_style: EXTERNAL, usage_design: EXTERNAL, inside_diameter: 7.817 INCHES MINIMUM AND 7.997 INCHES MAXIMUM IN, major_thickness: 0.187 INCHES NOMINAL IN, casehardening_indicator: NOT CASEHARDENED, material_hardness_rating: 45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM. This part is cataloged in the U.S.

Government catalog under NSN 5325-00-200-5197, indicating validated use in U.S. government and defense logistics supply chains. Available through authorized enterprise resellers and TPM (Third Party Maintenance) channels.

Verify compatibility with your specific system configuration before ordering.

WHERE IT FITS
MIL-R-21248B
NSN: 5325-00-200-5197
NIINs: 002005197, 002562861, 002562863, 005980850, 006632278, 008019703, 008045088, 010096841, 012550419, 013098766
FSC: 5325 — Fastening Devices
CAGE: 81349 — MILITARY SPECIFICATIONS PROMULGATED BY MILITARY DEPARTMENTS/AGENCIES UNDER AUTHORITY OF DEFENSE STANDARDIZATION MANUAL 4120 3-M
SPECIFICATIONS
materialSTEEL COMP 1060 OR STEEL COMP 1064 OR STEEL COMP 1065 OR STEEL COMP 1070 OR STEEL COMP 1074 OR STEEL COMP 1078 OR STEEL COMP 1080 OR STEEL COMP 1085 OR STEEL COMP 1086 OR STEEL COMP 1090
ring_styleEXTERNAL
usage_designEXTERNAL
inside_diameter7.817 INCHES MINIMUM AND 7.997 INCHES MAXIMUM IN
major_thickness0.187 INCHES NOMINAL IN
casehardening_indicatorNOT CASEHARDENED
material_hardness_rating45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM
cross-sectional_shape_styleRECTANGULAR
NSN5325-00-200-5197
COMPONENT DIAGRAM
BOLT / SCREW — THREAD VERIFICATION REQUIRED Hex HEAD LENGTH: — THREAD: — × — MATERIAL: — PN: MIL-R-21248B · OEM ⚠ VERIFY BEFORE ORDERING Verify thread pitch before ordering — metric (M8×1.25) ≠ imperial (5/16-18). Wrong thread = wrong part. Grade/class stamped on bolt head determines tensile strength ✓ BROKER TIP Grade/class stamped on head determines tensile strength. Grade 8 > Grade 5 > Grade 2. Always confirm head marking matches specification requirement PARTSTABLE TECHNICAL DRAWING — NOT TO SCALE
KEY FEATURES
•
MATERIAL HARDNESS RATING: 45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM
•
USAGE DESIGN: EXTERNAL
•
MATERIAL DOCUMENT AND CLASSIFICATION: FED STD 66 AISI 1066 OR 1069 OR 1070 OR 1072 OR 1074 OR 1075 OR 1078 OR 1080 OR 1084 OR 1086 OR 1090 FED STD SINGLE MATERIAL RESPONSE
•
CROSS-SECTIONAL SHAPE STYLE: RECTANGULAR
•
MAJOR THICKNESS: 0.121 INCHES MINIMUM AND 0.129 INCHES MAXIMUM IN
•
INSIDE DIAMETER: 4.887 INCHES MINIMUM AND 4.947 INCHES MAXIMUM IN
•
CASEHARDENING INDICATOR: NOT CASEHARDENED
•
RING STYLE: EXTERNAL
TECHNICAL CHARACTERISTICS
MATERIAL HARDNESS RATING45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM
USAGE DESIGNEXTERNAL
MATERIAL DOCUMENT AND CLASSIFICATIONFED STD 66 AISI 1066 OR 1069 OR 1070 OR 1072 OR 1074 OR 1075 OR 1078 OR 1080 OR 1084 OR 1086 OR 1090 FED STD SINGLE MATERIAL RESPONSE
CROSS-SECTIONAL SHAPE STYLERECTANGULAR
MAJOR THICKNESS0.121 INCHES MINIMUM AND 0.129 INCHES MAXIMUM IN
INSIDE DIAMETER4.887 INCHES MINIMUM AND 4.947 INCHES MAXIMUM IN
CASEHARDENING INDICATORNOT CASEHARDENED
RING STYLEEXTERNAL
SURFACE TREATMENTCADMIUM AND CHROMATE
MATERIALSTEEL COMP 1066 OR STEEL COMP 1069 OR STEEL COMP 1070 OR STEEL COMP 1072 OR STEEL COMP 1074 OR STEEL COMP 1075 OR STEEL COMP 1078 OR STEEL COMP 1080 OR STEEL COMP 1084 OR STEEL COMP 1086 OR STEEL COMP 1090
SUBSTITUTES & CROSS-REFERENCES 7
907920-0006Reference document
Same NSN cross-reference
Reference document — Advisory reference — outside the item-of-supply concept
5100-525Reference document
Same NSN cross-reference
Reference document — Advisory reference — outside the item-of-supply concept
68120475Reference document
Same NSN cross-reference
Reference document — Secondary reference
3100-525-ST-CDReference document
Same NSN cross-reference
Reference document — Secondary reference
5100-525MDReference document
Same NSN cross-reference
Reference document — Secondary reference
5100-525-S-MDReference document
Same NSN cross-reference
Reference document — Secondary reference
LIFECYCLE
NSN statusCancelled· U.S. Government catalog
Acquisition advice: Insurance item — stocked against contingency demandNo demilitarization required
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FREQUENTLY ASKED QUESTIONS
What is MIL-R-21248B?
MIL-R-21248B is a RING,RETAINING.
What parts can replace MIL-R-21248B?
There are 7 known substitutes for MIL-R-21248B: 907920-0006, 5100-525, 68120475 and 4 more. Substitute compatibility should be verified for your specific system.
What is the NSN for MIL-R-21248B?
MIL-R-21248B is cataloged in the U.S. Government catalog under NSN 5325-00-200-5197. This indicates validated use in U.S. government and defense supply chains.
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✓ PartsTable — the parts reference. Every fact cited to its source.
PartsTable Design LLC · partstable.com
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.
PartsTable commercial catalog: edition Unified commercial catalog snapshot through 2026-09-28, edition date not on file, retrieved 2026-09-28.