Grade of SS Wire?

You can't tell by looking. You can't use a magnet.

Chemical analysis is the only way I know of if you don't have documentation.

Get the MTR (Material test report) for the specific heat you were supplied with.

For determining the chemistry of the undiluted weld-metal derived from a welding consumable, a multi layer weld pad with dimensions approximately 40mm (l)*40mm (b)*15mm (h) is built ( min. of 6 layers) on a plate in flat position using stringer bead technique.

To avoid over heating the pad could be quenched in water periodically and this helps to overcome evaporation losses of base elements. Drillings or chippings are taken out from the top portion of the pad and analyzed by testing in the lab. But it is bit laborious and time consuming.

Alternatively, the welded pad could be ground and buffed to provide a smooth surface on the top and the specimen is subjected to spectra (spark) analysis. This is more easier and the results will be available in two to five minutes time as a print out. This method is more accurate and fast.

Sridhar.

If it's magnetic, it's 400 series. If it's not magnetic, it's 300 series. To further sort, you likely need chemical analysis.