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M7×1 — Full Fastener Spec
ISO 68-1 / ISO 261 · Coarse series · Tap drill, clearance hole, torque, strength and tool sizes — every number on one page.
Tap drill (75% thread)
6 mm
Nearest inch drill: B (0.2380") · Clearance hole (normal fit): 7.6 mm ·
8.8 torque: 17.6 N·m dry
Thread dimensions
Major diameter
7 mm
Pitch
1 mm
TPI (equivalent)
25.4
Pitch diameter
6.351 mm
Minor diameter
5.918 mm
Tensile stress area
28.86 mm²
Tap drill sizes for M7×1
Percent of thread is a trade-off: 75% is the shop default because the last 25% of engagement adds only a few percent of strength while roughly doubling tapping torque. Drop to 50–65% in tough or gummy material, or for blind holes where a snapped tap means scrapping the part.
| Thread engagement | Exact | Metric drill | Nearest inch drill |
|---|---|---|---|
| 50% | 6.35 mm | 6.4 mm | 0.2500" (E drill) |
| 65% | 6.156 mm | 6.2 mm | 0.2460" (D drill) |
| 75% | 6.026 mm | 6 mm | 0.2380" (B drill) |
| 85% | 5.896 mm | 5.9 mm | 0.2340" (A drill) |
Roll (form) taps need a larger hole than cut taps — add roughly
0.4× the pitch to the 75% cut-tap drill and confirm against your tap maker's chart.
Clearance hole for M7×1
| Fit | Hole | Use |
|---|---|---|
| Close | 7.4 mm | Located joints, dowel-like alignment |
| Normal | 7.6 mm | General assembly — use this unless you have a reason not to |
| Loose | 8 mm | Weldments, sheet stacks, tolerance build-up |
M7×1 torque specs
Calculated with the short-form equation T = K · D · F, using K = 0.2 (plain, dry, as-received steel) and a target clamp load of 75% of proof load — the standard preload target for a reusable joint.
| Grade | Dry | Lubricated | Dry (lb-ft) | Clamp load |
|---|---|---|---|---|
| 4.6 Low-carbon steel, general purpose | 6.82 N·m | 5.11 N·m | 5.03 lb-ft | 4.9 kN |
| 8.8 Medium-carbon, quenched & tempered — the default structural grade | 17.6 N·m | 13.2 N·m | 13 lb-ft | 12.6 kN |
| 10.9 Alloy steel, Q&T — high strength | 25.2 N·m | 18.9 N·m | 18.6 lb-ft | 18 kN |
| 12.9 Alloy steel, Q&T — highest common grade (socket head cap screws) | 29.4 N·m | 22 N·m | 21.7 lb-ft | 21 kN |
| A2-70 304 stainless, cold worked | 13.6 N·m | 10.2 N·m | 10.1 lb-ft | 9.7 kN |
The nut factor K dominates this result. Zinc-plated, waxed, anti-seize
and lubricated threads all shift K between roughly 0.10 and 0.25, which is a 2.5×
spread in torque for identical preload. If preload actually matters, torque-to-yield,
angle control or a load-indicating washer beats a torque wrench every time.
Tool sizes
Hex head wrench
11 mm
Hex key (socket head)
6 mm