SCARFING INSERT_SNMX 15-R

About scarfing

Scarfing is the removal of the weld bead that forms along the seam when steel strip is shaped and welded into a tube. The insert is mounted in a scarfing holder on the tube mill and cuts the bead flush with the tube surface while the tube moves continuously through the line.

T9335 grade characteristics

• Functionally graded substrate with medium grain size and relatively high cobalt content
• MT-CVD coating of medium thickness with a special surface finish
• Very high strength; suited to medium cutting speeds
• Handles continuous and heavily interrupted cuts, and very unfavourable machining conditions
• For material groups P (steel), M (stainless steel) and S (super-alloys)

Usage notes

• The R00 profile is for flat tube faces. For round tubes, select an SNMX 15-R insert whose profile radius matches the tube outside diameter.
• Use coolant where possible; it has a positive effect on tool life.
• Clamp the insert in a holder designed for SNMX 15-R inserts and make sure the insert seat is clean before indexing to the next cutting edge.
• Normally supplied in packs of 10 pieces.

The SNMX 15-R series from Dormer Pramet is a range of negative, double-sided scarfing inserts used on tube and pipe mills to cut away the external weld bead that forms when steel strip is shaped and welded into a tube. The SNMX 15-R00:T9335 is the flat-profile version of the series (profile radius R00), intended for the flat sides of square and rectangular tubes rather than round tubes.

Key features

• Square 90° negative insert with 0° clearance, usable on both faces for 8 cutting edges per insert
• Main cutting edge length 15.875 mm (0.625 inch) and thickness 8.15 mm (0.321 inch)
• Flat R00 cutting edge profile for square and rectangular tube sections
• T9335 grade: functionally graded WC-Co carbide substrate with an MT-CVD coating of medium thickness
• Very high edge strength for continuous and heavily interrupted cuts, and for unfavourable machining conditions
• Covers ISO application ranges P20-P45, M15-M40 and S15-S25

Applications

• External weld bead removal (OD scarfing) on welded square and rectangular tubes
• Steel, stainless-steel and super-alloy tube production
• Use in lever-lock scarfing holders for SNMX 15-R inserts, such as PXFNR 2525 R 15

Square (S) insert with 90° corners and a 0° clearance (N) on all sides, so both the top and bottom faces can be used.

• Main cutting edge length L: 15.875 mm, equal to the inscribed circle IC 15.875 mm
• Insert thickness S: 8.15 mm
• Central through hole for clamping, diameter D1: 5.16 mm
• Cutting edge profile: straight, with no concave radius (R00), to follow the flat faces of square and rectangular tubes
• Chipbreaker geometry on both faces

Choosing the right scarfing insert

• By tube shape: R00 (flat cutting edge) for square and rectangular tubes; radius versions (for example R11, R18, R25, R35, R40) for round tubes, chosen to match the tube outside diameter.
• By insert size: SNMX 15 (15.875 mm edge), SNMX 19 (19.05 mm edge) and SNMX 25 (25.4 mm edge) are available; larger inserts cover larger tube diameters.
• By workpiece material: T9335 (P20-P45, M15-M40, S15-S25) covers steel, stainless steel and super-alloys; grade 6640 (P20-P40, M20-M35) is offered for steel and stainless steel.
• By clearance: negative SNMX inserts are double-sided, giving more cutting edges; Pramet also offers positive SPUB inserts with 11° clearance.