LUTZ SKROO-ZON FILE HANDLE. - Self Threading: Hardened Steel Insert. - Wood Handle: Select New England Hardwood. T-6 SKROO-ZON # 6 FOR 10" FILES -. The Skroo-Zon handles are equipped with hardened steel inserts which cut a thread right onto the file tang creating an unsurpassed grip on the file and eliminating handle splitting issues.
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