Steel shot & grit · Size & tolerance table

Steel shot and grit sizes (SAE J444)

Standard: SAE J444 · ISO 11124-3 · sieve openings to ASTM E11

In the SAE system a shot number is the nominal particle diameter in ten-thousandths of an inch — S230 is about 0.023 in, or 0.58 mm. A grit number is the US standard sieve on which the bulk of that grit is retained — G25 is held mostly on the No. 25 sieve, which has 0.710 mm openings.

The diameters below follow from the designations and the sieve openings from ASTM E11; they are not the grading limits of the standard. Each SAE J444 size is defined by the share of the abrasive that must pass or be retained on a set of sieves, and real shot is a spread of sizes around its nominal one. ISO 11124-3 covers the same 14 shot and 11 grit sizes.

Cast steel shot

Shot size	Nominal diameter in	Nominal diameter mm	Typical use
S70	0.0070	0.18	Fine peening, light cleaning of small parts
S110	0.0110	0.28	Peening, cleaning thin and non-ferrous parts
S170	0.0170	0.43	Peening springs and gears, light descaling
S230	0.0230	0.58	Peening, cleaning sheet and light sections
S280	0.0280	0.71	General descaling of plate and sections
S330	0.0330	0.84	Plate and section blast lines, castings
S390	0.0390	0.99	Heavy plate and section descaling
S460	0.0460	1.17	Castings and forgings, heavy scale
S550	0.0550	1.40	Large castings, heavy descaling
S660	0.0660	1.68	Heavy castings
S780	0.0780	1.98	Very heavy castings and billets
S930	0.0930	2.36	Very heavy castings
S1110	0.1110	2.82	Very heavy castings
S1320	0.1320	3.35	Very heavy castings

Cast steel grit

Grit size	US sieve No.	Sieve opening mm	Typical use
G10	10	2.00	Heavy cleaning of large castings
G12	12	1.70	Heavy cleaning, deep profile
G14	14	1.40	Heavy cleaning, deep profile
G16	16	1.18	Heavy scale, deep anchor profile
G18	18	1.00	Heavy scale, deep anchor profile
G25	25	0.710	Coarse anchor profile before heavy coatings
G40	40	0.425	The common grit for paint surface preparation
G50	50	0.300	Finer profile for thin coatings
G80	80	0.180	Fine profile, light cleaning
G120	120	0.125	Very fine finishing
G200	200	0.075	Very fine finishing and etching

Notes

Grit is supplied in hardness grades — GP (softest), GL and GH (hardest) — in the same sizes.
The anchor profile a grit size gives depends on hardness, wheel or air speed and the steel; measure it rather than assume it.