GripEdge | 31-PC RPT™ 1/4", 3/8" & 1/2" Drive Semi-Long Metric & SAE Master Ball Hex Bit Socket Set

A ball hex bit solves an angle problem and creates a reach problem. The ball end lets the tool engage a recessed or obstructed socket head screw off-axis, but a standard-length bit socket often cannot get the ball far enough into the pocket, and a 6" long socket is more tool than a crowded bay has room for. The MBH31SLS splits the difference with 3" semi-long RPT™ Ball Hex bit sockets that reach into recessed hardware while staying maneuverable in tight spaces. This master set carries the full semi-long Ball Hex range in one case: 17 metric sizes from 3mm through 19mm and 14 SAE sizes from 1/8" through 3/4", across 1/4", 3/8", and 1/2" drive. It combines both 8-PC semi-long sets and adds fifteen 1/2" drive sizes beyond them, for the large socket head cap screws on suspension, driveline, and industrial equipment that no other ball hex socket reaches at an angle.

Every socket carries second-generation RPT™ Ball Hex geometry, so engagement behavior is consistent across the set, and each size sits on the square drive it belongs on, so the drive tool is never oversized for the fastener.

What's in the set

• 1/4" drive: 3mm, 4mm, 5mm, 6mm, 1/8", 9/64", 5/32", 3/16", 7/32"
• 3/8" drive: 7mm, 8mm, 9mm, 10mm, 1/4", 5/16", 3/8"
• 1/2" drive: 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 7/16", 1/2", 9/16", 5/8", 11/16", 3/4"

The engineering behind the grip

• RPT™ Ball Hex geometry. A standard ball end contacts the fastener on a narrow band and pushes material outward as it turns off-axis, which is how a ball hex rounds a socket head. The patented RPT™ ball profile is machined to hold grip through the pivot, delivering up to 50% more grip on new fasteners than standard ball hex tools and helping prevent rounding.
• 22.5 degree pivot. The second-generation ball geometry allows up to 22.5 degrees of off-axis engagement, a 50% increase over the first generation, for recessed and obstructed fasteners that a straight bit cannot approach.
• 3" semi-long reach. A slim, precision-machined bar at 3" overall gets into recessed pockets that defeat a standard-length socket, without the swing and clearance penalty of the 6" long series.
• Replaces standard Ball Hex tools. Use these first, every time, on good fasteners to prevent rounding rather than reaching for them after the damage is done.
• Material and marking. S2 steel with a zinc phosphate finish for strength, durability, and corrosion resistance, with oversized roll-stamped, ink-filled size markings for legibility in low light.
• Durable case with foam insert. Keeps every piece organized, protected, and easy to inventory.

Thirty-one sizes across metric and SAE, 1/4", 3/8" and 1/2" drive, and 3" of reach where a standard socket stops short.