Should I Add Extra Space to What the Datasheet Says?

[satchmo1991]

When a datasheet like the one attached gives "Mounting Hole Details", am I meant to drill the PCB holes with the measurements provided (in the example  2.1 x 1.8mm) or should I add extra room?

[Aleph Null]

There are tolerances to be accounted for: the legs could be an extra 0.2mm larger than the nominal size, also if the holes on the PCB are plated, that will reduce the diameter of the opening. How much wiggle room you need will depend on the manufacturer of the part as well as the PCB. I usually make a hole .25–40mm larger than the nominal size of the leg.

[madbean]

It's rare to find a drill bit that fits exactly for a lot of parts. I usually pick the next size up in millimeters or imperial.

[satchmo1991]

There are tolerances to be accounted for: the legs could be an extra 0.2mm larger than the nominal size, also if the holes on the PCB are plated, that will reduce the diameter of the opening. How much wiggle room you need will depend on the manufacturer of the part as well as the PCB. I usually make a hole .25–40mm larger than the nominal size of the leg.

It looks like in the image I attached the nominal size of the legs on the side is 2mm wide and the hole they mark out on  the right side is 2.1mm, so it looks like they are already accounting for some tolerances, but I think I'll take your advice and add 0.25mm to be safe.