Diamond Core Bit Diameter and Depth Chart for Electrical and Plumbing Openings

A buying and jobsite chart for matching diamond core bit diameter and working depth to common service openings.

Wrong core bit diameter wastes time on sleeves, clamps and firestop kits. Depth is equally important because many bits are sold by useful drilling length, not total length. Protec Tools supplies diamond core drill bits in metric and imperial sizes for contractors and OEM brands.

Common opening sizes to stock

20–32 mm: conduit and small cable runs
50–80 mm: plumbing sleeves and mid-size service holes
100–150 mm: HVAC and larger pipe penetrations
Confirm useful depth for thick walls, floors and double-wythe masonry

Match bit bond to material: soft bond for hard concrete and stone, harder bond for abrasive block. Use wet drilling when possible to protect diamonds and control dust. Check drill motor RPM against the bit diameter chart so large bits are not spun too fast.

Distributors can print a pocket diameter chart on packaging. Ask Protec Tools for OEM core bit kits that cover the most requested electrical and plumbing openings in your market.