Grit Size Conversion Chart

Reference chart for converting between different grit size standards (FEPA, ANSI, JIS, Micron, Mesh)

Grit Size Conversion Chart

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Important — these standards are NOT a 1:1 conversion

FEPA-P (FEPA-43-GB), ANSI/CAMI B74.18, and JIS R6010 use the same grit-number scale at coarse sizes but diverge sharply above roughly P400 / CAMI 600. The micron column below shows the FEPA-P particle size for the row's P-grade. The ANSI and JIS numbers in the same row are the closest grit-number neighbors, not the equivalent particle size in those standards. For ANSI/CAMI and JIS particle sizes at the fine end, use the divergence table below.

For most metallographic prep work, identify which scale your paper is sold under and stay in that scale — don't substitute "P1200" for "1200 grit" if your supplier ships ANSI/CAMI papers.

FEPA-P	ANSI (nearest no.)	JIS (nearest no.)	FEPA-P size (μm)	Mesh	Category
P12	16	16	1815	12	Very Coarse
P16	20	20	1324	16	Very Coarse
P20	24	24	1000	20	Very Coarse
P24	30	30	764	24	Coarse
P30	36	36	642	30	Coarse
P36	40	40	538	36	Coarse
P40	50	50	425	40	Coarse
P50	60	60	336	50	Medium
P60	80	80	269	60	Medium
P80	100	100	201	80	Medium
P100	120	120	162	100	Medium
P120	150	150	125	120	Fine
P150	180	180	100	150	Fine
P180	220	220	82	180	Fine
P220	240	240	68	220	Fine
P240	280	280	58.5	240	Very Fine
P280	320	320	52.2	280	Very Fine
P320	360	360	46.2	320	Very Fine
P360	400	400	40.5	360	Very Fine
P400	500	500	35.0	400	Very Fine
P500	600	600	30.2	500	Ultra Fine
P600	800	800	25.8	600	Ultra Fine
P800	1000	1000	21.8	800	Ultra Fine
P1000	1200	1200	18.3	1000	Ultra Fine
P1200	1500	1500	15.3	1200	Ultra Fine
P1500	2000	2000	12.6	1500	Ultra Fine
P2000	2500	2500	10.3	2000	Ultra Fine
P2500	3000	3000	8.4	2500	Ultra Fine

Where FEPA-P, ANSI/CAMI, and JIS diverge

Below ~P400, the same grit number means very different particle sizes in each standard. If your paper is labeled "1200 grit" with no other context, the actual abrasive size depends entirely on which standard the manufacturer used. Use this table to translate between them.

Grit number	FEPA-P (μm)	ANSI/CAMI (μm)	JIS R6010 (μm)
120	125	102	102
240	58	53	57
320	46	36	40
400	35	23	32
600	26	14.5	20
800	22	12.2	14
1200	15	~3	9.2
1500	13	~2	8
2000	10	—	6.7
2500	8.4	—	—

Source: FEPA 43-GB, ANSI B74.18, JIS R6010. Values rounded to typical manufacturer ranges. The handbook ladder used in our guides (P120 → P320 → P600 → P800 → P1200 in FEPA-P) corresponds roughly to US/CAMI 120 → 240 → 600 → 800 → ~1500 in actual particle size.

Notes

• FEPA-P: Federation of European Producers of Abrasives, P-grade (FEPA 43-GB). Most European and many international metallographic papers.
• ANSI/CAMI: ANSI B74.18, the standard used by most North American manufacturers (also called CAMI for Coated Abrasive Manufacturers Institute).
• JIS: JIS R6010 — Japanese Industrial Standard.
• Mesh: US Standard mesh size (particles per linear inch in the screen used to grade the abrasive).
• Particle-size figures are nominal; manufacturer-specific values can vary by ±10–20%.
• For acceptance work, verify abrasive standard and particle size on the manufacturer's data sheet.