1/4" Thru-Hardened Type 1 Yellow Zinc Steel Extra Thick Structural Flat Washer Made in USA / CROSS-SECTIONAL SHAPE STYLE: 1 RECTANGULAR HOLE DIAMETER: 0.281 INCHES MINIMUM AND 0.313 INCHES MAXIMUM PERIPHERAL SHAPE STYLE: 1 ROUND CENTER HOLE SHAPE STYLE: 1 ROUND THICKNESS: 0.090 INCHES MINIMUM AND 0.110 INCHES MAXIMUM OVERALL DIAMETER: 0.593 INCHES MINIMUM AND 0.657 INCHES MAXIMUM END ITEM IDENTIFICATION: MRAP - COUGAR CAT2 A2; MRAP - COUGAR CAT1 A2 SPECIAL FEATURES: STYLE: SAE EXTRA THICK; GRADE: THRU-HARDENED; MATERIAL: MEDIUM CARBON STEEL MATERIAL: STEEL OVERALL SURFACE TREATMENT: DICHROMATE ZINC OVERALL AND ZINC