---
type: "thread"
name: "M7×1"
designation: "M7×1"
series: "metric-coarse"
series_name: "ISO Metric Coarse"
system: "metric"
size_label: "M7"
pitch_in: 0.03937
pitch_mm: 1
basic_major_dia_in: 0.27559
basic_major_dia_mm: 7
basic_pitch_dia_in: 0.25
basic_pitch_dia_mm: 6.35
basic_minor_dia_in: 0.23295
basic_minor_dia_mm: 5.917
tap_drill: "6 mm"
tap_drill_dia_in: 0.23622
tap_drill_dia_mm: 6
tap_drill_thread_pct: 77
clearance_normal_drill: "7.5 mm"
tensile_stress_area_sqin: 0.044733
tensile_stress_area_sqmm: 28.86
internal_class_assumed: "6H"
standard: "ISO 68-1, ISO 261, ISO 262, ISO 965-1, ISO 898-1"
verified: "August 1, 2026"
url: https://shopmath.org/threads/metric-coarse/m7x1
---

# M7×1 Thread — Dimensions, Tap Drill & Clearance

The tap drill for M7×1 is 6 mm — 0.2362 in (6.000 mm) — which leaves 77.0% thread engagement with a cut tap. Basic pitch diameter is 0.2500 in (6.350 mm) and basic minor diameter is 0.2329 in (5.917 mm). Tapped-hole figures on this page assume a class 6H thread; drill sizes for 50–85% engagement are in the tap drill table below.

- **Series**: ISO Metric Coarse
- **Designation**: M7×1
- **Pitch**: 1.000 mm
- **Tap drill**: 6 mm
- **Standard**: ISO 68-1, ISO 261, ISO 262, ISO 965-1, ISO 898-1

## Basic Thread Dimensions for M7×1

| Property | Inch | Millimetre |
| --- | --- | --- |
| Basic major diameter | 0.2756 | 7.000 |
| Pitch | 0.0394 | 1.000 |
| Basic pitch diameter | 0.2500 | 6.350 |
| Basic minor diameter | 0.2329 | 5.917 |
| External thread root diameter | 0.2273 | 5.773 |
| Sharp V thread height (H) | 0.0341 | 0.866 |

_Basic dimensions are the theoretical values before any tolerance class is applied._

## Tap Drill Sizes for M7×1

Cut taps, from 50% to 85% thread engagement. The shop default is 75% — a 6 mm drill.

| Thread % | Target hole Ø (in) | Target hole Ø (mm) | Drill | Drill Ø (in) | Drill Ø (mm) | Actual thread % |
| --- | --- | --- | --- | --- | --- | --- |
| 50% | 0.2500 | 6.350 | 6.4 mm | 0.2520 | 6.400 | 46.2 |
| 60% | 0.2449 | 6.221 | 6.2 mm | 0.2441 | 6.200 | 61.6 |
| 65% | 0.2424 | 6.156 | 6.2 mm | 0.2441 | 6.200 | 61.6 |
| 70% | 0.2398 | 6.091 | 6.1 mm | 0.2402 | 6.100 | 69.3 |
| 75% (default) | 0.2372 | 6.026 | 6 mm | 0.2362 | 6.000 | 77.0 |
| 80% | 0.2347 | 5.961 | 6 mm | 0.2362 | 6.000 | 77.0 |
| 85% | 0.2321 | 5.896 | 5.9 mm | 0.2323 | 5.900 | 84.7 |

_Target hole Ø is the theoretical hole for the stated engagement. The drill column is the nearest size in the standard number/letter/fractional/metric index, and actual thread % is what that real drill produces._

## Clearance Hole Sizes for M7×1

The through-hole a M7×1 fastener passes freely, not the tapped hole.

| Fit | Drill | Hole Ø (in) | Hole Ø (mm) | Use |
| --- | --- | --- | --- | --- |
| Close | 7.3 mm | 0.2913 | 7.400 | Located joints, dowelled assemblies |
| Normal | 7.5 mm | 0.2992 | 7.600 | General assembly — the default |
| Loose | 7.9 mm | 0.3150 | 8.000 | Slotted or adjustable joints, weldments |

_Clearance holes per ISO 273 (metric) and ASME B18.2.8 (inch)._

## Tensile Stress Area of M7×1

| Property | in² | mm² |
| --- | --- | --- |
| Tensile stress area | 0.04473 | 28.86 |

The effective cross-section used to size a M7×1 fastener against a load. Multiply it by the material's allowable stress — the area itself carries no strength assumption.

## Other Thread Pitches in the Same Size as M7×1

A M7 fastener is not always M7×1. These are the other standard pitches cut on the same nominal size.

| Thread | Series | Pitch | Tap drill |
| --- | --- | --- | --- |
| [M7×0.75](https://shopmath.org/threads/metric-fine/m7x0.75.md) | ISO Metric Fine | 0.750 mm | 6.3 mm |

## Sources and Method for M7×1

### Basic dimensions

- **Source**: ISO 68-1 basic profile and ISO 898-1 tensile stress area; verified in docs/research/data-sourcing.md §3.2; diameter/pitch pairs: ISO 261 / ISO 262 diameter-pitch pairs via Wikipedia (CC BY-SA 4.0); cross-checked against threadlib metric_thread.csv (BSD-3) and FreeCAD CAM metric-internal-6H.csv (LGPL-2.1+); clearance holes: ISO 273 (metric) and ASME B18.2.8 (inch) via FreeCAD FeatureHole.cpp (LGPL-2.1+), cross-checked against bd_warehouse clearance_hole_sizes.csv (Apache-2.0)
- **Method**: computed+compiled
- **Verified against**: threadlib metric_thread.csv (BSD-3-Clause) and FreeCAD CAM metric-internal-6H.csv (LGPL-2.1+), agreeing cell-for-cell — 215 checks passed at 0.001 mm

### Tap drill sizes

- **Source**: Machinery's Handbook %-thread formula (geometry-derived); nearest-standard-drill-to-75% rule verified at 36/39 published chart rows in docs/research/data-sourcing.md §3.4
- **Method**: computed
- **Verified against**: D-P rule verified as exactly the 77.0% thread case

### Formulas

**Tap drill hole diameter, metric threads**

```text
hole Ø  =  D − (%thread ÷ 100) × 1.29904 × P

  D = basic major diameter (mm)
  P = pitch (mm)
```

_1.29904 = 2 × 0.64952, twice the engaged thread height per side on the 60° ISO profile._

**Actual thread engagement of the chosen drill**

```text
%thread  =  (D − drill Ø) ÷ (1.29904 × P) × 100
```

_The drill column rounds to a real drill; this is the engagement that drill actually leaves._

**Tensile stress area, ISO metric threads**

```text
As  =  (π ÷ 4) × ((d₂ + d₃) ÷ 2)²

  d₂ = basic pitch diameter
  d₃ = external thread root diameter
```

_ISO 898-1 form, evaluated on unrounded intermediates._

### Assumptions

- The headline tap drill assumes 75% thread engagement, the general shop default. Every engagement from 50% to 85% is in the tap drill table — change the assumption and the number moves.
- Tap drill figures are for cut taps. Drill diameters are nominal; a worn or run-out drill cuts oversize and reduces engagement further.
- Tapped-hole figures assume a class 6H internal thread, the general-purpose fit.
- Dataset scope: EXCLUDED: ISO 965-1 tolerance-grade formulas (not located — data-sourcing.md open item 2), 6g external limits (single-sourced), form tap drills, M68-M100 (verified demand cliff at M64).

**Data last verified**: August 1, 2026

## Common Questions About M7×1

### What is the tap drill size for M7×1?

The tap drill for M7×1 is 6 mm — 0.2362 in (6.000 mm). That leaves 77.0% thread engagement with a cut tap.

### What is the pitch diameter of M7×1?

The basic pitch diameter of M7×1 is 0.2500 in (6.350 mm).

### What is the minor diameter of M7×1?

The basic minor diameter of M7×1 is 0.2329 in (5.917 mm). That is the theoretical root of the internal thread, not the drilled hole size — see the tap drill table for the hole to drill.

### What is the thread pitch of M7×1?

M7×1 has a pitch of 1.000 mm, the distance from one thread crest to the next.

### What size clearance hole does a M7×1 fastener need?

close fit 7.3 mm (0.2913 in (7.400 mm)), normal fit 7.5 mm (0.2992 in (7.600 mm)), loose fit 7.9 mm (0.3150 in (8.000 mm)). The normal fit is the general-assembly default.

### What is the tensile stress area of M7×1?

The tensile stress area of M7×1 is 0.04473 in² (28.86 mm²). Multiply it by the fastener material's allowable stress to get a load.

## Related pages

- Smaller in ISO Metric Coarse: [M6×1](https://shopmath.org/threads/metric-coarse/m6x1.md) — tap drill 5 mm
- Larger in ISO Metric Coarse: [M8×1.25](https://shopmath.org/threads/metric-coarse/m8x1.25.md) — tap drill 6.8 mm
- All ISO Metric Coarse sizes: [ISO Metric Coarse thread chart](https://shopmath.org/threads/metric-coarse.md)
- Every thread series: [Screw thread reference](https://shopmath.org/threads.md)
- Cross-series chart: [Tap drill chart](https://shopmath.org/charts/tap-drill.md)

---

*Source: [ShopMath](https://shopmath.org/threads/metric-coarse/m7x1) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*