Tap Drill Size Chart

M60 x 5.5 Tap Drill Size

Tap drill

54.5 mm 2.1457 in

Use a 54.5 mm drill (2.1457 in) for 77.0% thread.

The drill size for a M60 x 5.5 tap is 54.5 mm (2.1457 in). If you are wondering what size drill bit a M60 x 5.5 tap needs, that is the one: it leaves 77.0% of thread, which is the figure standard tap and drill charts are built around. Below are the other holes you might want for this size - a larger drill for tough material, the form-tap hole, and the clearance holes for the bolt that goes in.

Every drill for M60 x 5.5

Tap drills and clearance drills for M60 x 5.5 (Metric coarse, 5.5 mm pitch). Percent of thread is the figure stored for each drill, which reproduces from the major diameter and pitch of M60 x 5.5.
Use Drill Decimal in mm % thread
Standard tap drill Cut tap, general use (D - P) 54.5 mm 2.1457 54.50 77.0%
Inch substitute Closest inch drill if you have no metric set 2″ 2.000 50.80 128.8%
Hard material Stainless, tool steel, anything that fights the tap 55.5 mm 2.185 55.50 63.0%
Form (roll) tap Theoretical 57.57 mm - starting point, check your tap maker's chart 57.5 mm 2.2638 57.50 —

Clearance holes for a M60 x 5.5 bolt

A clearance hole is not tapped. It is the hole in the part the bolt passes through, so it is always larger than the thread.

Clearance holes for M60 x 5.5 per ISO 273. Clearance depends on the bolt diameter alone, so every M60 thread shares these figures.
Fit Hole mm Hole in
Fine 62.00 2.4409
Medium 66.00 2.5984
Coarse 70.00 2.7559

M60 x 5.5 dimensions

Nominal dimensions for M60 x 5.5. The basic internal minor diameter is the hole a 100% thread would start from, which is why no tap drill is ever that small.
Dimension Inch mm
Major diameter 2.3622 60.00
Basic internal minor diameter 2.1278 54.05
Pitch 0.2165 5.50
Thread designation M60 x 5.5

What the hole looks like

Cross-section of a M60 x 5.5 tapped hole, drawn to scale The drilled hole is 54.5 mm, 2.1457 inches or 54.50 millimetres across. The tap cuts outward from that wall to the major diameter of 2.3622 inches. A 100 percent thread would reach in to the basic minor diameter of 2.1278 inches, shown as a dashed line; the difference is why this drill gives 77.0% of thread. major 60 mm drill 54.5 mm · 54.5 mm dashed = 100% thread at 54.05 mm
M60 x 5.5 in section, to scale. The accent line is the thread the tap cuts from a 54.5 mm hole; the dashed line is where the crest would sit at 100% thread. The gap between them is the 23.0% of thread this drill leaves behind.

Work out a different hole for M60 x 5.5

Pre-filled with M60 x 5.5. Change the material, the tap type, or which drills you actually own, and it picks the closest real drill and tells you the percent of thread you end up with. The tables above are the published figures and do not depend on this.

The general-purpose target

Tap type
Drills you have

Best drill you have, cut tap, 70% target

55 mm2.1654 in70.0% thread

Theoretical hole 55 mm

One size down, deeper thread54.5 mm 2.1457 in · 77.0%

One size up, easier tapping55.5 mm 2.185 in · 63.0%

For comparison, the published chart drill for M60 x 5.5 is 54.5 mm at 77.0% thread.

Notes on M60 x 5.5

Only pitch in the data
M60 x 5.5 is the only pitch this chart lists at 60 mm, so there is no fine or coarse alternative to confuse it with.
What the standard drill gives you
54.5 mm leaves 77.0% of thread (D - P). That is in the normal 65-80% band most shop charts aim for.
Stainless, tool steel and other tough material
55.5 mm opens the hole to 63.0% engagement. Less material for the tap to cut means less torque and less heat, at the cost of some thread depth.
Using a form (roll) tap
A form tap displaces metal instead of cutting it, so it needs a larger hole: 57.5 mm, against a theoretical 57.57 mm. Treat that as a starting point and check your tap maker's chart.
This size is usually bored, not drilled
At 60 mm, holes this big are normally bored or thread-milled rather than drilled and tapped. The 54.5 mm figure is here so the numbers are complete and so you can check a hole you already have; on a machine you would single-point or thread-mill the thread and bore the hole to size.
Closest inch size
1-1/2-6 is the nearest inch thread by diameter (38.1 mm against 60 mm). It is a planning reference only. The two are not interchangeable: the pitches differ, and a bolt from one will not run into a hole tapped for the other.

Related sizes

Next size up and down

Closest inch size

1-1/2-6 1-11/32″ · 1.3438 in · 34.13 mm · 72.1% 38.1 mm major against 60 mm

Not interchangeable. 1-1/2-6 is the nearest size by diameter, nothing more. The pitches differ, so a 1-1/2-6 fastener will not run into a M60 x 5.5 hole and forcing one will strip both.

Guides for tapping M60 x 5.5

Longer reads on the decisions behind the numbers above.

All guides →

M60 x 5.5 tap drill: common questions

What size drill bit do I need for a M60 x 5.5 tap?
A 54.5 mm drill, 2.1457 in. That leaves 77.0% of thread, which is the standard chart figure for M60 x 5.5.
What is the drill size for a M60 x 5.5 tap in inches?
The 54.5 mm tap drill measures 2.1457 in. If you only have inch drills, 2 in (2.000 in) is the closest, giving 128.8% thread.
What drill should I use for M60 x 5.5 in stainless steel?
Use 55.5 mm instead of 54.5 mm. It leaves 63.0% of thread rather than 77.0%, so there is less material for the tap to cut and less chance of snapping it.
What is the clearance hole for an M60 x 5.5 bolt?
For a medium fit, 66 mm per ISO 273. A clearance hole is not tapped; the bolt passes straight through it.
A 4 × 6 in card with the drills for this size.