ROUGHING END MILL_C609

Standard and shank

• Inch dimensions according to ANSI standard.
• All sizes have a Weldon shank. Weldon-type holders are typically used for HSS cutters, but Dormer notes that higher-quality tool holding gives better results with HSS-E cutters.

Tool material and coating

• HSS-E (HSCo) is harder and more wear resistant than HSS, but absorbs less shock and vibration. Unstable conditions can cause chipping or tool breakage, so use a rigid machine set-up and secure clamping.
• The TiCN coating lowers friction and improves wear resistance, helping chip flow and tool life.

Workpiece material groups (WMG)

Dormer Pramet classifies workpiece materials into six groups: P (steel and cast steel), M (stainless steel), K (cast iron), N (non-ferrous metals), S (high-temperature alloys) and H (hardened materials). Each group is divided into subgroups by structure or composition and by hardness or tensile strength. For every subgroup the catalogue gives a starting cutting speed in SFM together with a feed letter code; the letter code is read against the feed table for the tool diameter to obtain the feed per tooth (IPT).

Usage notes

• Cutting data from the manufacturer are starting values; adjust them to the machine, workholding, tool overhang and coolant conditions.
• Roughing end mills are intended for stock removal. Use a finishing end mill afterwards where tight tolerances or a fine surface finish are required.

The DORMER PRAMET C609 is a solid HSS-E roughing end mill with a square end and regular (medium) length of cut, built to remove material quickly in roughing operations. The cutter is made from cobalt-based high speed steel (HSS-E) and coated with titanium carbonitride (TiCN), and is supplied in inch sizes according to ANSI standard.

Key features

• HR regular fine-pitch roughing profile with a rounded chip-breaker form. Dormer states that the fine profile gives a stronger cutting edge and runs longer than conventional coarse-profile roughers.
• TiCN coating lowers the coefficient of friction and improves wear resistance, for better chip flow and longer tool life.
• Cobalt-based HSS-E substrate, harder and more wear resistant than standard HSS.
• 30° helix angle for general-purpose milling.
• Weldon shank for secure clamping in Weldon-type holders.
• 4 flutes on 1/4 to 3/4 inch diameters and 5 flutes on the 1 inch size.

Applications

• Shoulder milling, slot milling and ramping.
• Main workpiece materials: free machining steel, plain carbon steel, copper and copper alloys.
• The manufacturer also publishes starting cutting data for alloy and tool steel, stainless steel, cast iron, aluminium alloys, titanium and high-temperature alloys (see the cutting data table on this page).

C609 size range (inch)

Detailed data for C6091 (1 inch)

The C609 is a one-piece solid roughing end mill. It has a straight cylindrical Weldon shank with a clamping flat, followed by the fluted cutting section. The cutting edges carry a scalloped fine-pitch roughing profile along the helical flutes, and the tool has a square (flat) end.

• d1: cutting diameter
• d2: shank diameter
• l2: length of cut
• l1: overall length

For the 1 inch size (C6091) the manufacturer also lists a neck, with neck diameter 24.9 mm and neck length 56.3 mm.

Choosing a Dormer HSS-E roughing end mill

The fine-pitch profile of the C609 gives a stronger cutting edge and longer tool life than a coarse-profile rougher, while a coarse profile is intended for maximum metal removal in a single pass. Related series from the same Dormer catalogue:

Starting cutting data for C609 by workpiece material

Starting values from the Dormer end mill catalogue: cutting speed in SFM and a feed letter code. The feed per tooth for each letter code is given in the next table.

Feed per tooth (IPT) for HSS milling with 50% or more radial engagement

Values are in inch per tooth. Use the row closest to the tool diameter.