Metric coarse

M6 × 1.0

Tap drill 5 mm for a M6 × 1.0 thread - major Ø 6 mm, pitch 1 mm (≈25.4 TPI (converted)).

Tap drill
5 mm
5 mm · ≈77% thread

Profile

Thread form & key diameters

Major Ø 6 mmP 1 mm60°Minor Ø 4.773 mm · Pitch Ø 5.351 mmM6 × 1.025.4 TPI · 60° form

Dimensions

Dimensions, drill sizes and wrench sizes for M6 × 1.0.
DesignationM6 × 1.0
Major (outside) diameter6 mm · 0.2362"
Pitch1 mm · ≈25.4 TPI (converted)
Pitch diameter5.351 mm · 0.2106"
Minor diameter (external)4.773 mm · 0.1879"
Minor diameter (internal)4.918 mm · 0.1936"
Recommended tap drill5 mm · ≈77% thread
Clearance holeClose 6.4 · Normal 6.6 · Loose 7 mm
Hex head (across flats)10 mm
Socket key (across flats)5 mm

Wrench sizes follow ISO 4014 / ISO 4017. Older DIN 931 / DIN 933 bolts differ at several sizes (M10 = 17, M12 = 19, M14 = 22, M22 = 32) - check the bolt before choosing a spanner.

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.

Proof-load preload and estimated tightening torque for M6 × 1.0 by fastener grade or property class.
Grade / classStress areaPreloadTorque
Class 8.820.1 mm²8.75 kN10.5 N·m
Class 10.920.1 mm²12.53 kN15 N·m
Class 12.920.1 mm²14.64 kN17.6 N·m

Strengths are ISO 898-1:2013 Table 3 for d ≤ 16 mm. Class 8.8 is size-banded - 580 MPa proof at or below 16 mm, 600 MPa above - while 10.9 and 12.9 hold one value across the range.

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.

Put M6 × 1.0 on a job sheet

The bolt schedule collects the fasteners for one job onto a single sheet - tap drill, wrench size, grade and tightening torque on every line, taken straight from pages like this one. Free schedules hold 3 lines and are saved in this browser only.

Open bolt schedule

What tap drill do I need for M6 × 1.0?

For a M6 × 1.0 thread, drill the hole with a 5 mm tap drill (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 6 mm and a pitch of 1 mm (≈25.4 TPI (converted)).

To pass a M6 × 1.0 bolt through a part rather than thread it, use a clearance hole: Close 6.4 · Normal 6.6 · Loose 7 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.

Frequently asked questions

What drill size do I need to tap a M6 × 1.0 thread?

Drill 5 mm before tapping M6 × 1.0. That leaves roughly 77% thread engagement, the usual target for a strong hole that still taps cleanly.

Is M6 × 1.0 a coarse or fine thread?

M6 × 1.0 is a metric coarse thread. Coarse is the default pitch for M6: when a drawing or supplier says just M6, it means this 1 mm pitch.

What size clearance hole does a M6 × 1.0 bolt need?

Drill 6.4 mm for a close fit, 6.6 mm for a normal fit or 7 mm for a loose fit (ISO 273). A clearance hole lets the M6 × 1.0 bolt pass through the part instead of threading into it.

How much torque should I use on a M6 × 1.0 bolt?

Estimated tightening torque for M6 × 1.0 runs from 10.5 N·m (Class 8.8) to 17.6 N·m (Class 12.9), targeting 75% of proof load with a dry nut factor of K = 0.20. Lubricated threads need noticeably less torque.

Same diameter

Other M6 threads

Closest inch sizes

Inch equivalents for M6 × 1.0

Nearest standard Unified sizes by major diameter. These are substitutes by size only - the thread forms are not interchangeable, so never run one into the other.

Tightening torque

M6 × 1.0 by grade

One page per grade, each printing the nut factor, the diameter and the clamp load it used rather than a single number.

Grade markings and strength bands: ISO property class 4.6, ISO property class 8.8, ISO property class 10.9, ISO property class 12.9.

Nearby sizes

More metric coarse threads