S12 MVJNR 3 — boring bar, 3/4" bar diameter. Made in the USA by RMC Tooling.
Steel-shank indexable boring bar from RMC Tooling, machined in the United States. Ground shank, standard indexable geometry, and a rigid clamping system sized to the bar diameter — the combination that keeps chatter down at the depths where boring bars usually give up.
Sized by minimum bore, so start there: pick the largest bar diameter your bore will clear. Every clamp, lock pin, seat and screw in this bar is a stocked RMC service part, listed below.
These are the service parts RMC lists for this style and insert size. Availability of replacement parts varies by item.
| Insert | VNM_-332 (e.g. VNMG 332) — 3/8" I.C. · 3/16" thick · 1/32" nose radius |
| Seat / shim | IVSN-322 |
| Lock pin | NL-34L |
| Clamp | CL-30 |
| Clamp screw | XNS-59 |
| Seat screw | S-34 |
See all RMC spare parts & hardware →
Not sure how to read an insert code? Turning insert designation explained.
Specifications decoded from the RMC toolholder identification system (RMC 2020 catalog, page 2).
RMC toolholder availability varies. When replenishment is required, estimated time to ship is 4–6 weeks. Please contact us for availability of this item.
Estimated time to ship is measured in calendar days, from order placement until your order is handed to the carrier. Carrier transit time is additional. Orders may ship sooner. We accept orders awaiting replenishment; please contact us before ordering if you need a specific shipping date.
See our Shipping Policy for details.
