As LAB said. If it only has one value, then this will be the continuous rating.
No, that wasn't what I said. A 1 1/4"/31mm glass fuse marked 35A can certainly be the blow rating.
The fuse rating can also be stamped on the metal end cap . https://www.ebay.ie/itm/2x-35A-BLOW...-CAR-MOTOR-FUSE-6-3-x-31mm-/382856091018
"These 35A fuses are marked according to the modern Lucas
regime (metric / post decimalisation) system whereby the marked rating is the BLOW rating and the continuous rating is half that marked (17/17.5A (Amp) CONTINUOUS)"https://www.triumph-spares.co.uk/35-amp-glass-fuse-fuse35https://rrsl.co.uk/product/fuse35a-1-1-4-glass-fuse-35a-blow/