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# How Big Should clearance holes be?

## How Big Should clearance holes be?

Clearance Hole Size for Bolts and Screws (Metric)

Nominal Thread Diameter/mm Clearance Hole Sizes/mm
2.0 2.2 2.6
2.5 2.7 3.1
3.0 3.2 3.6
4.0 4.3 4.8

How are clearance holes calculated?

The LMC clearance hole also can be calculated by adding the diameter of the fastener and the diameter of the fastener head and then dividing the sum by two. This method of selecting the LMC clearance hole size is a rule of thumb that will yield the largest hole that will fit under the head of the fastener.

What is the typical clearance hole for a 5/16 bolt?

0.3125
Clearance Hole Size for Bolts and Screws (Imperial)

Size of Screw Clearance Hole Drills
Close Fit
5/16 0.3125 0.3230
3/8 0.3750 0.3860
7/16 0.4375 0.4531

### What is clearance hole?

clearance hole (plural clearance holes) A hole through an object which is large enough to enable threads of a screw or bolt to pass through but not the head of the screw or bolt.

Are clearance holes necessary?

This can be a very important. Of course, without a proper-sized clearance hole the ability to draw the first piece of material tight to the second is compromised. Without a clearance hole, the screw threads are biting into the first piece, then thread into the second.

How much tolerance does a bolt hole need?

ISO Tolerances For Bolt Fastener and Holes Table Chart ISO 286

Size Tolerance Zone in mm (Internal Hole Features)
over to H7
6 10 +0.015 0
10 18 +0.018 0
18 30 +0.021 0

## What is bolt hole clearance?

A clearance hole is a hole through an object which is big enough to enable threads of a screw or bolt to pass through but not the head of the screw or bolt. It allows a screw to pass through it without the threads biting into the material.

Are bolt holes always clearance holes?

Most bolt holes are made with “standard” clearance and are considered a normal fit. A normal fit provides relatively accurate positioning of assembled components while still allowing for slight misalignment.