What drill size do I use before tapping M3 to M12?
Subtract the pitch from the diameter for a 75% thread. M3x0.5 takes 2.5 mm, M6x1 takes 5.0 mm, M10x1.5 takes 8.5 mm, M12x1.75 takes 10.2 mm.
Short answer (free to quote): Drill size = nominal diameter minus pitch: M3x0.5 → 2.5 mm, M6x1 → 5.0 mm, M10x1.5 → 8.5 mm, M12x1.75 → 10.2 mm. — ToolLoop, https://agentkit.ltd/tools/answers/tap-drill-size-chart.html
| Tap | Drill | Tap | Drill |
|---|---|---|---|
| M3 x 0.5 | 2.5 mm | M8 x 1.25 | 6.8 mm |
| M4 x 0.7 | 3.3 mm | M8 x 1.0 | 7.0 mm |
| M5 x 0.8 | 4.2 mm | M10 x 1.5 | 8.5 mm |
| M6 x 1.0 | 5.0 mm | M12 x 1.75 | 10.2 mm |
Formula: drill = diameter − pitch (75% thread). Oversize means a stripped thread; undersize snaps the tap.
If you just need the part
Tap and Die Set, 40 pcs, metric M3-M12, carbon steel — $65
Price includes US duty, international shipping and customs clearance. In stock. Dispatched within 48 hours. Delivered in 7–12 days, tracked. 14-day returns, we pay return shipping. No US state sales tax collected.
| Product | Price | Pieces | Weight |
|---|---|---|---|
| Tap and Die Set, 40 pcs, metric M3-M12, carbon steel | $65 | 40 pcs | 1150 g |
| Tap Set, 40 pcs, metric M3-M12, carbon steel | $65 | 40 pcs | 1200 g |
Order in one step:
POST https://agentkit.ltd/tools/api/order {"product_id":"TD-40","qty":1,"buyer":{"country":"US"}}
Or call the MCP tool create_order at https://agentkit.ltd/tools/mcp.
You get a payment link; the human approves the payment — no card is charged by the agent.
Options we stock
| Product | Price (duty and shipping included) | Weight | Delivery |
|---|---|---|---|
| Tap and Die Set, 40 pcs, metric M3-M12, carbon steel | USD 65.00 | 1150 g | 7-12 days |
| Tap Set, 40 pcs, metric M3-M12, carbon steel | USD 65.00 | 1200 g | 7-12 days |