5/8 Short Arm Alloy Steel Hex Key is part of the driver shelf that supports cap screws, set screws, shoulder screws, and pipe plugs. The ASME B18.3 width band is 0.6225-0.6250 in.; the key is held just under nominal so it enters an in-tolerance socket and bears on the flats.
Equipment installation crews use individual keys to support field setup, access panels, and machine leveling work. The Short Arm key is the compact member of the pair, while the Long Arm version covers deeper socket access.
For industrial purchasing and maintenance teams, Cold Headers helps match width, series, and catalog identity. Review the 5/8 in. width, Short Arm format, short-leg length, and arm length before ordering. The listed B and C ranges keep the tool geometry tied to this exact catalog row. That context helps purchasing compare the driver geometry without adding unsupported performance claims.
Call 773-775-7900 or email Sales@coldheaders.com for pricing, availability, or a quote.
