Irwin Record IWTM130 Clamp Heads, Black ,22.0 cm*6.0 cm*31.0 cm

Amazon

A bar clamp of any length can be easily made using a piece of timber 1in thick Cast iron head and slides incorporating large thrust surfaces High-quality steel handle and screw with pin attached by welded chain, Weight: 2.5132697868 pounds, Manufacturer: Stanley Black & Decker

Zoro Tools

M130 A low cost alternative to a full size sash clamp. Clamp heads have a cast grey iron head and slide with a steel main screw. Clamp heads are designed to be fitted to a wooden batten 25mm (1) thick by 38mm (1) wide and any length.