// capability 05 · threads and flush seats
Tapping & countersinking
Add threads and bolt hole features to any sheet-metal part.
What we offer
We tap specified holes and produce countersunk seats as part of complete fabricated jobs, from prototypes to repeat batches.
Tell us the thread designation and pitch, fastener type, quantity and any critical depth or flushness requirement.
Why choose tapping?
Fix parts together directly, with integrated threads added during manufacturing.
Thin sheet may not offer enough engagement for the load or service life. In that case a press-fit insert or rivet nut can provide a stronger/cheaper captive thread without tapping.
Why choose countersinking?
Countersinking lets a compatible flat-head fastener sit flush or below the surface. This is useful for sliding interfaces, clean visible faces, close-fitting assemblies and places where a projecting screw head would interfere.
Designing tapped and countersunk features
Call out the complete thread
State the thread standard, nominal size and pitch. Mark any unusual depth, fit or positional tolerance explicitly. We keep all metric and BSP threads as standard.
Leave enough material
The material must be thick enough to allow enough threads for engagement. We can suggest an insert, rivet nut or design change when direct machining is not robust.
Name the mating fastener
For a countersink, identify the fastener standard or included angle and whether the head must be flush.
What to send
Include a STEP model or DXF where available, plus a PDF drawing that calls out the threads and countersink locations. If the part must accept a specific screw, send its standard or a sample. On our quoting system, you can specify holes directly for tapping and countersinking in the 3D viewer.
What follows
Once secondary machining is complete, the same team can add inserts, rivet nuts and blind rivets, continue into welding and assembly, and protect the finished part with powder coating.
Show us the fastener and the finished fit
We can suggest threading options around how the part actually needs to work.
We deliver across Hampshire, Wiltshire, Berkshire and Dorset, and nationwide by parcel and pallet.
Request a quote Next: fixings & hardware
Prefer to talk it through? Call 01264 527 017. Or send a drawing: DXF, DWG, PDF, STEP/STP, ZIP or images, up to 20 MB.