BARREL END MILL_S791

Standards and tolerances

• Manufactured to Dormer Pramet standard
• Shank to DIN 6535 HA, shank diameter tolerance h6
• Nose radius RE tolerance ±0.01 mm; tangential radius PRFRAD tolerance ±0.01 mm
• Dimension symbols (DC, RE, PRFRAD, DCON MS, APMX, OAL, NOF) according to ISO 13399

Application range

• Operations: semi-finishing and finishing of contoured surfaces (copy milling) and turn-milling
• Workpiece materials (ISO): P steel and cast steel, M stainless steel, K cast iron, N non-ferrous metals, S heat-resistant super-alloys and titanium

Usage notes

• Designed for 5-axis machining of complex components; program the tool path with the barrel profile (RE and PRFRAD) so that the tangential radius, not only the nose, is in contact with the wall.
• The nose radius can also be used for fillet milling and as a general ball nose cutter.
• Cutting data in the manufacturer catalogue are starting values; depending on working conditions, adjust them by ±25%.
• Make sure the machine, tool holder and workpiece clamping are rigid, and wear eye protection during machining.

Dormer S791 Barrel End Mill – Solid Carbide, AlCrN Coated

The S791 is an advanced barrel-shaped end mill from Dormer Pramet for efficient 5-axis machining in die and mould and aerospace applications. Its cutting profile combines a nose radius for fillet milling with a large tangential form radius for machining curved and deep-wall surfaces. It delivers excellent surface quality and is suitable for semi-finishing and finishing in steels, stainless steels, cast iron and super-alloys.

Key features

• Larger tangential radius with more overlap than a conventional ball nose end mill, giving a greater area of contact with the workpiece, longer tool life and shorter cycle time
• Fewer passes, leading to more than 50% machining time savings
• Better surface quality, minimizing the time spent on polishing
• Keeps all the benefits usually associated with a robust ball nose end mill
• Positive rake angle (8°) for a smooth cutting action in stainless steels and super-alloys, reducing the risk of work-hardening
• 3-flute and 4-flute designs for more productivity than common 2-flute ball nose cutters
• Micrograin carbide for extreme hardness and wear resistance, increasing tool life in difficult-to-machine materials
• AlCrN coating for thermal stability, reduced friction, excellent wear resistance and prolonged durability

Typical applications

Copy milling of contoured surfaces and turn-milling, especially steep and curved walls on complex components machined on 5-axis machines in die and mould making and the aerospace industry.

DC = cutting diameter · RE = nose radius · PRFRAD = tangential (profile) radius · DCON MS = shank diameter · APMX = maximum depth of cut · OAL = overall length · NOF = number of flutes

Tolerances: DCON MS h6 · RE ±0.01 mm · PRFRAD ±0.01 mm

The S791 is a one-piece solid carbide tool made up of a cylindrical plain shank and a barrel-shaped cutting part at the tip.

• Shank: cylindrical plain shank to DIN 6535 HA; shank diameter DCON MS equals the cutting diameter DC (6.00 – 16.00 mm), tolerance h6.
• Cutting part: 3 or 4 helical flutes with a 30° helix; maximum depth of cut APMX 22.00 – 31.00 mm.
• Side profile: the cutting edge follows a large tangential radius PRFRAD of 75.0 – 95.0 mm, which gives the barrel form used for steep and curved walls.
• Tip: the tangential radius connects to a nose radius RE of 1.00 – 3.00 mm, used for fillet milling and ball nose type machining.
• Overall length OAL: 67.0 – 90.0 mm.

Choosing by workpiece material (ISO group)

The ranges cover the material sub-groups in the Dormer Pramet catalogue. Use the upper end for softer grades such as free-machining steel or aluminium, and the lower end for harder or tougher grades such as hardened tool steel or Ni- and Co-based alloys.

Feed per tooth fz (mm)

Valid for a width of cut of 0.05 × DC or less. Find the feed code for your material in the table above, then read fz at the nearest diameter.

Machining example: barrel end mill vs ball nose end mill

Workpiece DIN 1.2311 (WMG P3.3, 300 – 320 HB), finishing an angled wall of 10°, tool diameter 10 mm, air cooling.