Sand Casting — How HT200 and HT250 Vise Bodies Are Made — Stavalk

Sand casting is the most direct route from a drawing to a bench vise body, and it remains the process behind virtually every cast iron vise in production. This article walks through how Stavalk produces HT200 and HT250 grey cast iron bodies, from pattern construction to the finished casting ready for machining.

Patterns and molding

Every body design starts as a pattern — a full-size replica of the part, made from high-density wood or aluminum, which produces the cavity in the sand mold. Because a bench vise body is not symmetrical, the pattern is split and the two halves are mounted on splitter plates that index the molding boxes. For high-volume models we use matchplate molding, where both halves of the pattern sit on a single plate and the mold is formed in one box.

Green sand molding

The mold is made from green sand — a mixture of silica sand, bentonite clay, and water. The prepared sand is compacted around the pattern either by jolt-squeeze machines for standard bodies or by automated molding lines for high-volume runs. The compacted mold is then split, the pattern is drawn out, and cores — sand shapes that form internal voids like the slide channel — are set into the cavity. Finally, the two mold halves are closed and clamped, ready for pouring.

Melting and pouring

The charge metal for grey cast iron is a blend of pig iron, steel scrap, and returns from the foundry's own gating systems, melted in a cupola or induction furnace. The chemistry is adjusted to hit the target grade: HT200 for standard workshop vises, HT250 when the design calls for higher tensile strength, such as 8" and 10" heavy-duty bodies. Molten iron is poured at roughly 1,300–1,400 °C through the gating system into the mold cavity, filling it completely as the sand vents gases through its natural permeability.

Solidification and shakeout

As the iron cools, the characteristic grey cast iron structure forms — a matrix of iron with graphite flakes that provide its vibration damping and self-lubricating wear characteristics. Once solid, the mold is broken apart in the shakeout and the casting is separated from the sand, which is reclaimed and recycled for the next mold. The casting then receives a preliminary shot blast to remove residual sand before moving to the machining section.

HT200 and HT250 properties worth casting for

Grey cast iron earns its place in bench vise bodies for three reasons: excellent vibration damping that stops work chatter, good machinability meaning precise slide faces and threads, and a graphite structure that lubricates moving surfaces. The grade difference — HT200 at roughly 200 MPa tensile strength and HT250 at 250 MPa — lets us match strength to duty cycle. Standard workshop bodies use HT200; heavy-duty and professional lines use HT250.

From casting to finished body

The raw casting is not yet a usable vise body. It moves through heat treatment where needed, then CNC milling of the slide faces and mounting base, drilling and tapping of the mounting holes, and final surface finishing — the powder coat that protects it for the workshop environment. The whole chain, from melt chemistry to finished body, is documented per batch, which is why every Stavalk shipment carries material certificates you can audit.