Metric fine

M52 × 3.0

Tap drill 49 mm for a M52 × 3.0 thread — major Ø 52 mm, pitch 3 mm (8.47 TPI).

Tap drill
49 mm
49 mm · ≈77% thread

Profile

Thread form & key diameters

Major Ø 52 mmP 3 mm60°Minor Ø 48.319 mm · Pitch Ø 50.052 mmM52 × 3.08.47 TPI · 60° form

Dimensions

DesignationM52 × 3.0
Major (outside) diameter52 mm · 2.0472"
Pitch3 mm · 8.47 TPI
Pitch diameter50.052 mm · 1.9705"
Minor diameter (external)48.319 mm · 1.9023"
Minor diameter (internal)48.753 mm · 1.9194"
Recommended tap drill49 mm · ≈77% thread
Clearance holeClose 54 · Normal 56 · Loose 62 mm
Hex head (across flats)80 mm

ISO 273 clearance holes (fine / medium / coarse).

Tightening torque estimate

Target preload is 75% of proof load; torque is estimated from T = K · F · d.

Grade / classStress areaPreloadTorque
Class 8.81900 mm²826.52 kN8595.8 N·m
Class 10.91900 mm²1182.77 kN12300.8 N·m
Class 12.91900 mm²1382.28 kN14375.7 N·m
These figures assume a nut factor of K = 0.20 (dry / as-received steel). K captures thread and head friction and can swing torque by 30% or more — a lubricated joint needs noticeably less. Change the lubrication assumption in the bolt-torque calculator.

What tap drill do I need for M52 × 3.0?

For a M52 × 3.0 thread, drill the hole with a 49 mm tap drill (49 mm — the standard D − P rule) before tapping. That produces roughly 77% thread engagement, the usual target for a strong, tappable hole. The mating bolt has a major diameter of 52 mm and a pitch of 3 mm (8.47 TPI).

To pass a M52 × 3.0 bolt through a part rather than thread it, use a clearance hole: Close 54 · Normal 56 · Loose 62 mm.

All values are generated from the standard thread formulas (ISO 68-1 / ASME B1.1) and published standard tables — not hand-entered. See the full reference.

Same diameter

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