Weha Radial Arm Finger Tip — Reverse Thread (20x23xM12) | Single Head | Granite, Marble & Quartz

The Weha Radial Arm Finger Tip (Reverse Thread, 20x23xM12) is a single-head diamond finger tip for edge profiling on granite, marble, quartz, and quartzite using radial arm machines. This is the reverse thread version — required for left-hand spindles on radial arm machines where standard right-hand thread finger tips would unscrew during operation. Compatible with Fab King and similar single-head radial arm setups. Use for edge profiling, sink cutouts, and countertop edge shaping.

Standard vs. Incremental — Which Do You Need?

Weha offers two reverse thread finger tip options in the 20x23xM12 format:

• This product (SKU 30515RV) — Standard reverse thread finger tip for general edge profiling on granite, marble, and quartz
• Incremental Quartzite version (SKU 30517RV) — Stepped segment design for harder materials like quartzite where single-pass profiling risks chipping

Reverse Thread — Why It Matters

On radial arm machines, spindle rotation direction determines whether a standard or reverse thread finger tip is required. Using the wrong thread direction causes the finger tip to unscrew during operation — a safety hazard and source of tool damage. Always confirm your machine’s spindle direction before ordering.

Specifications

• SKU: 30515RV
• Thread: Reverse M12 (left-hand)
• Head type: Single head
• Compatible machines: Fab King, radial arm machines with M12 spindle
• Applications: Granite, marble, quartz, quartzite, sink cutouts, edge profiling
• Weight: 0.2 lb

Works Well With

• Weha Radial Arm Finger Tip (20x23xM12) — Standard thread version for right-hand spindles
• Weha Incremental Quartzite Radial Arm Finger Tip (Reverse Thread) — For quartzite and hard stone
• Weha Radial Arm Finger Tip (1/2 Gas x 12mm) — Alternative thread adapter
• Weha Vacuum Brazed Zero Tolerance Wheel — Profile wheel for radial arm use
• Weha Rock Dog Router — Stone profiling machine

Further Reading

Which Weha Finger Bit Do You Need? CNC vs Radial Arm — Complete Buying Guide → — Full comparison of all Weha finger bits and finger tips by machine type, material, and application.