Engineering tools for faster specification.

Narrow a fastener down to a standard, a size and a hole before you send the RFQ.

Metric clearance hole and tap drill sizes

Clearance holes to ISO 273 in fine, medium and coarse, and the tap drill for each thread — read straight off the table by diameter.

Which standards are direct equivalents, and — where they are not — exactly which dimensions differ and by how much.

Every diameter and length we publish, straight to the size page with its dimensions, hole sizes and quotation route.

Standard, size, material, finish, quantity and destination are enough to begin.