Overmoulded Grip and Handle Sub-Assembly with Heat-Set Inserts

A grip is bought as a sub-assembly, not as a part, and the difference is the assembly step the buyer does not have to run. The programme receives a finished grip with the inserts in place and the bond cured, and what it is really buying is the removal of three operations from its own line: insert installation, overmoulding and bond verification. That is why grips are quoted per sub-assembly with the verification included, and why a grip quoted as a loose part is a different product from the same geometry quoted as a sub-assembly.

We supply two-shot overmoulded grip and handle sub-assemblies with heat-set brass inserts, ready for the buyer's assembly line.

The two-shot structure

The sub-assembly is a rigid core, usually PP, ABS or PA, with a TPE overmould covering the grip zone. The core carries the inserts and the geometry that mates to the buyer's product; the overmould carries the feel. The bond between them is the specification, because a grip that debonds in a wet or oily hand is a warranty return, and the bond is set by the substrate preparation, the shot window and the adhesion promoter in the TPE compound rather than by anything that can be adjusted at the press after the fact.

Heat-set inserts and why not moulded-in

Inserts are installed after moulding rather than moulded in, for three reasons: a heat-set insert can be replaced if it is installed wrong, the installation is verified with a torque reading rather than inferred from the shot, and the core tool does not have to hold the inserts during the shot, which lowers the tool cost and the cycle risk. The insert is heated and pressed into a boss that is cored to a defined wall, and the boss is designed so the insert is surrounded by material rather than sitting on a thin skin. Retention is verified per lot with a pull test and a torque test, with the break mode reported, because an insert that pulls clean was under-supported in the boss.

Specification

What the buyer's line receives

The sub-assembly arrives with the inserts installed, the bond verified and the lot card attached, which is what removes the buyer's three operations. Programmes that want to own the verification take the same parts on lot cards with the test records attached and run their own incoming inspection, which is the same sub-assembly at a lower handling cost. The kitting option extends to mixed part numbers per set, where the grip ships with the trigger, the latch or the cover that shares the assembly station.

Compliance

Grip sub-assemblies declare to REACH for the material stream, with the core compound, the TPE compound and the adhesion promoter declared as three lots because each migrates differently. Tool and appliance programmes add RoHS where the sub-assembly ships with an electronics-bearing product, and the declaration names the insert metal separately. As across this site, the copy stays on the industrial specification and makes no performance claim that the programme's own testing has not established.

Related reading

Our mechanical sub-assembly programme covers the gearbox and latch family, and the sub-assembly category lists the full range.