How much clearance should you include in through-hole components holes?

Is there a general rule as to how much clearance you should add to through-hole components' holes to allow them to fit easily? For example, if I have a component with 1mm pin diameter, what should the diameter of the holes for it's pads be?
  • 0.1mm is too tight toward the high end if you’re designing for automatic insertion of parts with bent leads.
  • Usually 0.8mm is okay for most leads except fat diode leads, for which you can use 1.0mm.
  • Usually 1.3mm holes are specified for 1mm pins (for example on terminal block datasheets).
  • Sometimes 1.5mm which is really, really loose.

If the leads are flat or square rather than round, you can go a bit tighter on the diagonal dimension, assuming a round hole. For really flat leads, it’s better to specify a slot.

If you’re using some kind of special part, such as a staked connector or press-fit part, pay attention to the tolerances.

Read More: Through Hole PCB Assembly

#PCB Assembly #PCB Design

Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.
Picture of Oliver Smith

Oliver Smith

Oliver is an experienced electronics engineer skilled in PCB design, analog circuits, embedded systems, and prototyping. His deep knowledge spans schematic capture, firmware coding, simulation, layout, testing, and troubleshooting. Oliver excels at taking projects from concept to mass production using his electrical design talents and mechanical aptitude.

What Others Are Asking

Why should we bake bare PCB?

The assembly note states: Bake bare PCBs in a clean and well ventilated oven prior to assembly at 125*C for 24 hours. Why is this necessary?

How do you mount electronics on a vehicle chassis safely?

I want to implement a control system I designed for a light electric motorbike. I would like to mount it as professionally as possible on the chassis. It consists of a power system pcb and a SAMC21 development board which I’ll merge later once this all works properly. I have tried screwing it directly on the aluminium chassis but have found that shocks and vibrations from the horn disturbed the system or even destroyed it upon large shocks. Is there a specific way car and motorcycle manufacturers mount their electronics to make their system as robust as possible?

Read Detailed Advice From Blog Articles

Scroll to Top