GRS 003-699 Thermo-Loc Form Block

Create custom, repeatable workholding in minutes. This 2-sided Thermo-Loc® Form Block lets you form precision fixtures from thermoplastic materials (Thermo-Loc, Jett Sett, Plastiform) for secure, chatter-free engraving, stone setting, and finishing. Use the small cavity grid without the divider to make rigid, single-piece holders for pendants, medallions, and small parts. Drop in the aluminum divider to build a flexible, hinged holder that clamps long or irregular items—such as bracelet blanks—firmly and evenly.

Key Features

• Two fixture styles from one tool: rigid single-piece holders or flexible hinged holders.
• Aluminum divider quickly creates a living-hinge effect for long workpieces; remove after forming.
• Multiple cavity sizes support a wide range of jewelry parts, from small fobs to longer blanks.
• Works with most engraving blocks and vises, BenchMate-style fixtures, and similar setups.
• Designed for thermoplastic fixturing materials (Thermo-Loc, Jett Sett, Plastiform) that soften with heat and harden at room temperature.

What’s Included

• Thermo-Loc® Form Block (two-sided)
• Aluminum divider (removable)

How to Use

Rigid holder (without divider)

1. Select a slot sized to your part. Fill the slot with heated Thermo-Loc and pack firmly to create a level clamping ledge.
2. Add more heated material on top, pre-shape to your item, then press the workpiece in and form the edges up to secure it.
3. Before it fully cools, create a small pry relief next to the part for easy removal. After cooling, lift the finished fixture out of the block.

Flexible hinged holder (with divider)

1. Pre-fill the hinge cavity to about 1/8" (3 mm) with heated Thermo-Loc along the length you need.
2. Insert the aluminum divider until it bottoms out; its top should sit roughly 1/4" (6 mm) above the block surface.
3. Pack Thermo-Loc into both jaw cavities up to the height of the divider—do not allow material to bridge over the divider.
4. Place the workpiece on the divider and gently work each side up to grip it. Let cool, remove the assembly, then take out the divider—the hinged fixture is ready.

Bench Tips

• Heat a larger lump of Thermo-Loc and cut pieces as needed to save time; cool finished fixtures with air or water (avoid trapping moisture against steel workpieces).
• For quick touch-ups while forming, you can briefly warm the block/divider in a microwave—remove the workpiece first and heat in short bursts.
• In use, place the hinged fixture in your vise or BenchMate; tightening the jaws compresses the two halves to clamp the work securely. Recenter as you work to keep operations near the vise center.

Compatibility / Applications

• Engraving, stone setting, layout, and finishing where anti-chatter support is critical.
• Holds flat stock, bracelet blanks, pocket knives, pendants, fobs, and other small components.

California Prop 65 Warning:
Cancer and Reproductive Harm. www.P65warnings.ca.gov.