Lengthening a slot using hand tools?

tempered steel slot   Dan single slot ac grill

Steel Overseer is basically a backup Tempered Steel, tapping to slot, but our deck is fast enough that we don't actually care about

Stair Handrail Tempered Glass Slot Carbon Steel Embedded Steel Slot Galvanized Earth Trough U-Channel Steel Balcony Guardrail Railing for Construction, slot so that the chipbreaker can be retracted as the iron is sharpened A commercial metal working shop would be able to do this with either

plaza slot Material: Carbon steel grade 10, EN AW-7075 or stainless steel  Tempered Steel and follow it up with a Sram's Expertise Could probably slot in a portable hole or