Venier Caliper (150)

The four are worth knowing because people routinely use only one of them. The large lower jaws measure external dimensions: the diameter of a shaft, the thickness of a plate, the width of a component. The small upper jaws measure internal dimensions: the bore of a hole, the inside of a tube, the gap between two faces. A rod extends from the tail as you open it, giving a depth gauge for holes and recesses. And the stepped ends of the jaws give a step measurement, for the height of one surface above another. One tool, four jobs.

At 150mm it covers the great majority of workshop components, and it is the size that lives on a bench.

The scale is applied by laser engraving, which is a durability specification worth understanding. On a caliper the graduations are extremely fine, and the vernier scale in particular depends on being able to read which of a row of closely spaced lines aligns with another. Printed markings on a tool handled daily in oil and swarf wear and smudge, and a caliper whose vernier lines have become indistinct is no longer a precision instrument. Engraved lines are cut into the metal and stay. The satin finish helps for the same reason — it does not throw glare back at you when you are trying to read fine lines under a bench lamp.

The buyers are engineering and machine shops, vehicle and motorcycle mechanics, toolrooms and maintenance workshops, technical training workshops, quality inspection, and hardware dealers supplying precision trades.

Three habits. Close the jaws fully and check the scale reads zero before measuring; a caliper that has been dropped or has dirt in the jaws reads wrong from the start. Use light, consistent pressure — a caliper squeezed hard reads under size, and the commonest source of inconsistent readings is two people gripping differently. And wipe the jaws and the workpiece first, because a chip of swarf between jaw and part is worth more than the tolerance you are trying to measure. Message us on WhatsApp for a price.