Haskins-Strand Standard Duty metal drive core. The cable diameter is 5/16". Both ends are fluted.
On the Standard model, both cable ends look like this:
On the Heavy Duty model, one end is fluted and the other has a screw-in bolt end.
When you replace the drive shaft or casing, follow this guide.
You can print it out. You can also use the guide to troubleshoot any problems you might have in operation. It is almost always the result of loose connections or a damaged drive shaft or casing.
Maintenance
All hand fish scalers have a rotating metal drive shaft that should be lubricated when installed and monthly in use. We recommend this Food Grade Super Lube Grease available from Grainger.