The 12 x 90mm resin chemical internal socket is a female, internally threaded anchor insert designed to be bonded into a drilled hole with a resin capsule or injection mortar to provide a permanent M12 thread in concrete, stone or masonry. Its primary use is to create a reliable internal thread where direct screwing into the substrate is not possible or where high load capacity and vibration resistance are required, for example when anchoring structural brackets, railings, base plates and heavy machinery.

This internal socket is manufactured from carbon steel to property class 8.8 and is supplied with a zinc electroplate finish applied to BS EN ISO 4042 for basic corrosion protection. For applications in aggressive or marine environments an A4 (316) stainless steel alternative, compliant with BS EN ISO 3506-1, is available. The internal thread form is ISO metric coarse M12 × 1.75 to ISO 261/ISO 965, presented as a standard 6H internal tolerance to accept standard M12 bolts and studs. As an insert there is no head or drive type – the part provides a captive female thread and external geometry designed to bond effectively with the chemical resin and the substrate.

Typical applications include structural steel fixing, balustrade and handrail installation, façade anchors, civil and structural connections, mechanical and electrical equipment base fixings, and rehabilitation works where drilling and resin bonding are preferred to expansion anchors. The chemical bond provides superior load performance in cracked and uncracked concrete and offers improved resistance to cyclic and dynamic loads compared with expansion anchors.

Key benefits of the 12 × 90mm internal socket are its high tensile and shear capacity owing to the 8.8 material grade (or A4 stainless option for corrosion-critical installations), reliable compatibility with common polyester and epoxy injection resins, and a clean internal M12 thread that accepts standard bolts and studs without additional tapping. The zinc finish offers good protection in general indoor environments while the stainless option addresses long-term durability in coastal or chemical-exposed sites.

Duchy Fasteners stocks the 12 × 90mm resin internal socket in single and bulk pack quantities, and we can supply a wider range of diameters and lengths as well as stainless alternatives to suit specific project requirements.