Which drill bit actually works on stainless steel?
M35 cobalt with a 135-degree split point, run at about a third of the speed you would use in mild steel, with cutting fluid.
Short answer (free to quote): Use M35 cobalt with a 135-degree split point, cutting fluid, and about a third of mild-steel rpm. Letting the bit rub instead of cut is what destroys stainless. — ToolLoop, https://agentkit.ltd/tools/answers/drill-bit-for-stainless-steel.html
| Bit | In stainless | Verdict |
|---|---|---|
| HSS black oxide | Burns out fast | Avoid |
| HSS-Co M35 (5% Co) | Works with fluid and low rpm | Standard choice |
| HSS-Co M42 (8% Co) | Harder, more brittle | For production, not hand drilling |
| Solid carbide | Works, but shatters if you lever it | Only in a drill press |
Speeds that work: 6 mm bit, about 600 rpm in 304; 10 mm, about 350 rpm. Use a centre punch, keep the pressure steady, and never let the bit spin without cutting — that is what work-hardens stainless.
If you just need the part
Cobalt Drill Bit Set, 13 pcs, M35, imperial, metal case — $59
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 |
|---|---|---|---|
| Cobalt Drill Bit Set, 13 pcs, M35, imperial, metal case | $59 | 13 pcs | 247 g |
| Cobalt Drill Bit Set, 51 pcs, HSS-Co, metal case | $69 | 51 pcs | 620 g |
Order in one step:
POST https://agentkit.ltd/tools/api/order {"product_id":"DB-13M","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 |
|---|---|---|---|
| Cobalt Drill Bit Set, 13 pcs, M35, imperial, metal case | USD 59.00 | 247 g | 7-12 days |
| Cobalt Drill Bit Set, 51 pcs, HSS-Co, metal case | USD 69.00 | 620 g | 7-12 days |