Question about sandpaper grits

[chaiguy]

I have some sandpaper that my brother in law gave me (he's a mechanical engineer specializing in materials), and I told him that I'm getting into straight razor restorations. Since a lot of this is right up his alley he's been quite interested.

Anyhow, he mentioned there are two different grit number systems (European and American I believe he said). In particular, he gave me some silicon carbide that says "1200/4000" and another that says "P1200". The 1200/4000 stuff is significantly finer than the P1200 so I presume the P1200 is using the same system as the 4000 side of the 1200/4000, whatever that is.

My question is what system are people using when they talk on here, because I've only ever seen single numbers given.

[DPflaumer]

I have a stack with 220, 320, 400, 600, 1500, and 2000.

When I am done, the blade is very near mirror finished.

[Neil Miller]

I think there are four main systems - the three in this table, and the JIS japanese one.

From the table, you can see that the P1200 is roughly equivalent to CAMI 600 grit. CAMI is standard for North America, FEPA (the "P" system) is European.

Regards,
Neil

[chaiguy]

Aha, according to Sandpaper - Wikipedia, the free encyclopedia the "P" refers to the ISO/FEPA system, the other one being CAMI. In higher grits, the CAMI numbers are smaller, thus the "P" would be the 4000 side of 1200/4000.

Guess I could have checked that before asking, but now it's here in case anyone else has a similar question.

[chaiguy]

I think there are four main systems - the three in this table, and the JIS japanese one.

From the table, you can see that the P1200 is roughly equivalent to CAMI 600 grit. CAMI is standard for North America, FEPA (the "P" system) is European.

Regards,
Neil

So in the list DPflaumer just gave me, those would be CAMI numbers?

[DPflaumer]

The list I gave is P

[chaiguy]

The list I gave is P

Ok, that makes more sense. Thanks for clearing that up.

Am I to assume then that most people use the "P" grits when just conversing on here, despite CAMI being the supposed standard in the US?

[DPflaumer]

I would guess that most people mean P

[Pete_S]

Ok, that makes more sense. Thanks for clearing that up.

Am I to assume then that most people use the "P" grits when just conversing on here, despite CAMI being the supposed standard in the US?

Yes. We all "P" freely here.

[chaiguy]

Yes. We all "P" freely here.