Gibraltar 20413G Step Block Clamp Set 52 Pc 3/8-16

Product Description

The GIBRALTAR 20413G is a 52-piece step block and clamp set designed for workholding applications on milling machines, drill presses, and similar machine tool setups. The set accepts a 3/8-16 stud thread and fits 1/2-inch T-slots, making it suitable for standard machining tables found in job shops and maintenance facilities. Step blocks measure 1 inch in width, and studs are available in six lengths: 3, 4, 5, 6, 7, and 8 inches, giving the technician flexibility to clamp workpieces of varying heights without reaching for additional hardware. The full kit ships as a matched set, eliminating the need to source components separately.

This set is used in metalworking environments where parts must be secured to a machine table for milling, drilling, or boring operations. It is appropriate for both production shops and toolroom applications. The 7/8-inch T-slot nut width and 1/2-inch T-slot size are common specifications on knee mills, Bridgeport-style machines, and similar equipment. Machinists, toolmakers, and maintenance mechanics are the primary installers and users of this type of workholding hardware.

Key Features

• 52-piece complete set — studs, coupling nuts, flange nuts, serrated end clamps, step blocks, T-slot nuts, holder, and T-slot cleaner included
• 3/8-16 stud thread size compatible with standard machine table hardware
• Fits 1/2-inch T-slots with 7/8-inch T-slot nut width
• Six stud lengths (3, 4, 5, 6, 7, and 8 inches) accommodate varying workpiece heights
• 1-inch step block width for stable, consistent clamping surface
• Includes T-slot cleaner for table maintenance during setup

Compatibility

Designed for use with machine tables fitted with 1/2-inch T-slots and 3/8-16 threaded hardware, consistent with Bridgeport-style knee mills and similar general-purpose milling machines.

Installation Notes

Machine power should be locked out and the spindle fully stopped before adjusting any workholding setup. Studs should be tightened evenly and clamps positioned as close to the workpiece as practical to minimize deflection. Inspect T-slots for chips or debris using the included T-slot cleaner before seating T-slot nuts. Workholding setup and adjustment should be performed by a qualified machinist or toolmaker familiar with proper clamping technique.