ABP is the designation for the manufacturer, although I do not know who this particular manufacturer is. Check the links in thread725-63797 to learn who ABP is.
The other characters are supposed to be A4-70, which is a material designation according to ISO 3506-1 Mechanical properties of corrosion-resistant stainless-steel fasteners -- Part 1: Bolts, screws and studs. This is an austenitic stainless steel (nominally type 316), with ultimate tensile strength of 700 MPa.
Regards,
Cory
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
Is your screw non-magnetic ? If not, then you are probably mis-reading for A4-70 which is a stainless steel material defined by ISO3506-1. ABP is the registered mark of ABP Stainless screw Corp. in Thailand