At One Place

M48×5 thread

M48×5 tap drill
43 mm
Clearance hole 50 mm · 75 mm hex

M48×5 is a coarse metric thread with a 48 mm (1.890") major diameter and 5 mm pitch. Tap it with a 43 mm drill; drill 50 mm to pass a bolt through.

The numbers

Designation
M48×5
Major diameter
48 mm / 1.890"
Minor diameter
42.587 mm
Pitch
5 mm pitch
Tap drill (75% thread)
43 mm — 43 mm
Clearance hole (close fit)
50 mm / 1.969"
Hex across flats
75 mm

How to measure what you have

  1. Measure across the thread crests with calipers. A used M48×5 reads a little under 48 mm — the crests are truncated by the standard, then worn and plated, so anything from about 47.6 mm up is consistent with this size.
  2. Measure the pitch: put a rule against the threads and count the distance over ten crests, then divide by ten. This one should give 5 mm.
  3. A thread pitch gauge settles it in seconds and costs very little. Guessing between a coarse and a fine thread of the same diameter is the usual way a thread gets stripped.

Tightening torque

Typical torque
5150–6950 N·m
3799.2–5127.0 lb·ft

Plain steel property class 8.8 or SAE grade 5, dry threads, tightened to about 65% of yield. Lubricated threads reach the same preload at 20-30% less torque. Where the manufacturer publishes a figure — spark plugs, wheel nuts, cylinder heads — use theirs.

Where this size turns up

  • Very large flange and foundation bolting
  • Turbine and generator holding-down bolts
  • Heavy forging and press equipment

Common questions

What size drill for an M48×5 tap?
43 mm (43 mm), which gives about 75% thread engagement.
What clearance hole for M48×5?
50 mm for a close fit — enough to pass the bolt without slop.
What spanner fits M48×5?
75 mm across the flats on a standard hex head.

Related pages

Sources

  1. Official vendor product documentation — At One Place
  2. Typical range compiled from manufacturer specifications — At One Place

How these figures are compiled and checked