ThreadRef

Sizes · Metric (ISO)

Metric fine

M45 × 1.5

Tap drill 43.5 mm for a M45 × 1.5 thread — major Ø 45 mm, pitch 1.5 mm (16.93 TPI).

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Tap drill
43.5 mm
43.5 mm · ≈77% thread

Profile

Thread form & key diameters

Major Ø 45 mmP 1.5 mm60°Minor Ø 43.16 mm · Pitch Ø 44.026 mmM45 × 1.516.93 TPI · 60° form

Dimensions

DesignationM45 × 1.5
Major (outside) diameter45 mm · 1.7717"
Pitch1.5 mm · 16.93 TPI
Pitch diameter44.026 mm · 1.7333"
Minor diameter (external)43.16 mm · 1.6992"
Minor diameter (internal)43.376 mm · 1.7077"
Recommended tap drill43.5 mm · ≈77% thread
Clearance holeClose 46 · Normal 48 · Loose 51 mm
Hex head (across flats)70 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 8.81492.5 mm²649.24 kN5843.2 N·m
Class 10.91492.5 mm²929.09 kN8361.8 N·m
Class 12.91492.5 mm²1085.8 kN9772.2 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 M45 × 1.5?

For a M45 × 1.5 thread, drill the hole with a 43.5 mm tap drill (43.5 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 45 mm and a pitch of 1.5 mm (16.93 TPI).

To pass a M45 × 1.5 bolt through a part rather than thread it, use a clearance hole: Close 46 · Normal 48 · Loose 51 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 M45 threads

M45 × 2.0Tap 43 mmØ 45 mm · pitch 2 mmM45 × 3.0Tap 42 mmØ 45 mm · pitch 3 mmM45 × 4.0Tap 41 mmØ 45 mm · pitch 4 mmM45 × 4.5Tap 40.5 mmØ 45 mm · pitch 4.5 mm

Nearby sizes

More metric fine threads

M45 × 2.0Tap 43 mmØ 45 mm · pitch 2 mmM45 × 3.0Tap 42 mmØ 45 mm · pitch 3 mmM45 × 4.0Tap 41 mmØ 45 mm · pitch 4 mmM42 × 2.0Tap 40 mmØ 42 mm · pitch 2 mmM42 × 3.0Tap 39 mmØ 42 mm · pitch 3 mmM42 × 4.0Tap 38 mmØ 42 mm · pitch 4 mmM48 × 1.5Tap 46.5 mmØ 48 mm · pitch 1.5 mmM48 × 2.0Tap 46 mmØ 48 mm · pitch 2 mm