Metric fine

M52 × 2.0

Tap drill 50 mm for a M52 × 2.0 thread — major Ø 52 mm, pitch 2 mm (12.7 TPI).

Tap drill
50 mm
50 mm · ≈77% thread

Profile

Thread form & key diameters

Major Ø 52 mmP 2 mm60°Minor Ø 49.546 mm · Pitch Ø 50.701 mmM52 × 2.012.7 TPI · 60° form

Dimensions

DesignationM52 × 2.0
Major (outside) diameter52 mm · 2.0472"
Pitch2 mm · 12.7 TPI
Pitch diameter50.701 mm · 1.9961"
Minor diameter (external)49.546 mm · 1.9506"
Minor diameter (internal)49.835 mm · 1.962"
Recommended tap drill50 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 8.81973.2 mm²858.35 kN8926.8 N·m
Class 10.91973.2 mm²1228.33 kN12774.6 N·m
Class 12.91973.2 mm²1435.51 kN14929.3 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 × 2.0?

For a M52 × 2.0 thread, drill the hole with a 50 mm tap drill (50 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 2 mm (12.7 TPI).

To pass a M52 × 2.0 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

Other M52 threads

Nearby sizes

More metric fine threads