ISO Metric Coarse · M48×5
M48×5 Thread — Dimensions, Tap Drill & Clearance
https://shopmath.org/threads/metric-coarse/m48x5 · data verified August 1, 2026
The tap drill for M48×5 is 25 mm — 0.9842 in (25.000 mm) — which leaves 354.1% thread engagement with a cut tap. Basic pitch diameter is 1.7619 in (44.752 mm) and basic minor diameter is 1.6766 in (42.587 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
- M48×5
- Pitch
- 5.000 mm
- Standard
- ISO 68-1, ISO 261, ISO 262, ISO 965-1, ISO 898-1
Tap drill · 354.1% thread · cut tap
25 mm
- Drill Ø
- 0.9842in
- Drill Ø
- 25.000mm
- Clearance (normal)
- 25 mm
Assumes 75% thread engagement with a cut tap and a class 6H hole. That drill actually leaves 354.1% thread.
Basic Thread Dimensions for M48×5
| Property | Inch | Millimetre |
|---|---|---|
| Basic major diameter | 1.8898 | 48.000 |
| Pitch | 0.1968 | 5.000 |
| Basic pitch diameter | 1.7619 | 44.752 |
| Basic minor diameter | 1.6766 | 42.587 |
| External thread root diameter | 1.6483 | 41.866 |
| Sharp V thread height (H) | 0.1705 | 4.330 |
Basic dimensions are the theoretical values before any tolerance class is applied.
Tap Drill Sizes for M48×5
Cut taps, from 50% to 85% thread engagement. The shop default is 75% — a 25 mm drill. Deeper engagement means more holding strength and more torque on the tap.
| Property | Target hole Ø | Nearest standard drill | Property | |||
|---|---|---|---|---|---|---|
| Thread % | in | mm | Drill | in | mm | Actual thread % |
| 50% | 1.7619 | 44.752 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 60% | 1.7363 | 44.103 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 65% | 1.7235 | 43.778 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 70% | 1.7107 | 43.453 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 75%default | 1.6980 | 43.129 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 80% | 1.6852 | 42.804 | 25 mm | 0.9843 | 25.000 | 354.1 |
| 85% | 1.6724 | 42.479 | 25 mm | 0.9843 | 25.000 | 354.1 |
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 — the number that matters at the machine. Values are for cut taps. Tapped-hole figures assume a class 6H hole.
Clearance Hole Sizes for M48×5
The through-hole a M48×5 fastener passes freely, not the tapped hole.
| Property | Property | Hole Ø | Property | |
|---|---|---|---|---|
| Fit | Drill | in | mm | Use |
| Close | 25 mm | 1.9685 | 50.000 | Located joints, dowelled assemblies |
| Normal | 25 mm | 2.0472 | 52.000 | General assembly — the default |
| Loose | 25 mm | 2.2047 | 56.000 | Slotted or adjustable joints, weldments |
Clearance holes per ISO 273 (metric) and ASME B18.2.8 (inch). The drill column is the nearest standard drill at or above the specified hole diameter.
Thread Class Limits for M48×5
Manufacturing limits for classes 6H. A gauge reading outside these bands is a reject, not a judgement call.
| Property | Class 6H | |
|---|---|---|
| Limit | in | mm |
| Major Ø min | 1.8898 | 48.000 |
| Pitch Ø max | 1.7751 | 45.087 |
| Pitch Ø min | 1.7619 | 44.752 |
| Pitch Ø tolerance | — | 0.335 |
| Minor Ø max | 1.7046 | 43.297 |
| Minor Ø min | 1.6766 | 42.587 |
Tensile Stress Area of M48×5
The effective cross-section used to size a M48×5 fastener against a load. Multiply it by the material's allowable stress — the area itself carries no strength assumption.
| Property | in² | mm² |
|---|---|---|
| Tensile stress area | 2.28339 | 1473.15 |
The formula this value comes from is in the sources section below.
Sources and Method for M48×5
- Basic dimensionscomputed+compiled
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)
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
Part computed from the standard's formulas, part compiled from agreeing public sources.
- Tap drill sizescomputed
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
Verified against D-P rule verified as exactly the 77.0% thread case
Computed from the standard's formulas, then checked against published tables.
- Class limitscompiled
threadlib metric_thread.csv (BSD-3-Clause) and FreeCAD CAM metric-internal-6H.csv (LGPL-2.1+), agreeing cell-for-cell
Verified against two independent published datasets agreeing cell-for-cell to 0.001 mm; ISO 965-1 formulas not located, so these are compiled not computed
Compiled from independent public sources that agree cell-for-cell.
- Formula
Tap drill hole diameter, metric threads
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
%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
As = (π ÷ 4) × ((d₂ + d₃) ÷ 2)² d₂ = basic pitch diameter d₃ = external thread root diameter
ISO 898-1 form, evaluated on unrounded intermediates — recomputing it from the rounded diameters shown above lands within 0.01%.
- Assumptions
- The headline tap drill assumes 75% thread engagement, the general shop default. Every other 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
How to Cite This M48×5 Reference
Citation
ShopMath. "M48×5 Thread — Dimensions, Tap Drill & Clearance." ShopMath, verified August 1, 2026, https://shopmath.org/threads/metric-coarse/m48x5
BibTeX
@misc{shopmath-threads-metric-coarse-m48x5,
title = {M48×5 Thread — Dimensions, Tap Drill & Clearance},
author = {{ShopMath}},
year = {2026},
howpublished = {\url{https://shopmath.org/threads/metric-coarse/m48x5}},
note = {Data verified 2026-08-01}
}Permanent URL
https://shopmath.org/threads/metric-coarse/m48x5
Common Questions About M48×5
What is the tap drill size for M48×5?
- The tap drill for M48×5 is 25 mm — 0.9842 in (25.000 mm). That leaves 354.1% thread engagement with a cut tap.
What is the pitch diameter of M48×5?
- The basic pitch diameter of M48×5 is 1.7619 in (44.752 mm). For a class 6H thread it runs 1.7619 in (44.752 mm) to 1.7751 in (45.087 mm).
What is the minor diameter of M48×5?
- The basic minor diameter of M48×5 is 1.6766 in (42.587 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 M48×5?
- M48×5 has a pitch of 5.000 mm, the distance from one thread crest to the next.
What size clearance hole does a M48×5 fastener need?
- close fit 25 mm (1.9685 in (50.000 mm)), normal fit 25 mm (2.0472 in (52.000 mm)), loose fit 25 mm (2.2047 in (56.000 mm)). The normal fit is the general-assembly default.
What is the tensile stress area of M48×5?
- The tensile stress area of M48×5 is 2.28339 in² (1473.15 mm²). Multiply it by the fastener material's allowable stress to get a load.