S2 tool steel. Blast finish steel bits provide a firm hold to the fastener. Highly resistant to wear and tear for long life. 1/4 In. hex shank fits all standard bit holders and hand-held drivers. Size: T5 TORX Length: 1" Shank Diameter: 1/4" Hex WARNING: THIS PRODUCT CONTAINS CHEMICALS KNOWN TO THE STATE OF CALIFORNIA TO CAUSE CANCER OR OTHER REPRODUCTIVE HARM -