Режущие и зажимные инструменты Hoffmann Group 2026 - страница 921

GBP 57 Profile broaching (tumbling) Hexagon, square, Torx® and Torx Plus® profiles – created in seconds: Internal profile External profiles Preparation (bore) Preparation (workpiece) To protect the cutting edge and reduce the machining time, To protect the cutting edge and reduce the machining time, pre-drill the workpiece with the largest possible bore diameter. pre-turn the workpiece to the smallest possible diameter. It is essential that the workpiece diameter is less than the radius diameter of the hexagonal profile. Guide values bore ⌀ d (AF plus oversize): Guide values for workpiece ⌀ D (circle ⌀ less oversize): Width across flats AF Positive oversize Width across flats AF Material Negative oversize Hexagon Hexagon Square mm N % mm % % 3 to 14 < 750 – 1 to – 7 2 to 25 + 0 to + 2 +5 3 to 14 < 900 - 3 to - 10 Guide values for bore ⌀ d (Torx® / Torx Plus®): Torx® Hole Bore oversize Torx® Hole Bore oversize For hexagonal profiles a guide value for the diameter of the circumscribed circle ⌀ 0.00 – ⌀ 0.00 – is: ⌀ D = Width across flats × factor 1.16. mm mm mm mm mm mm Example calculation of radius diameter calculation (see diagram below): TX5 1 +0.05 TX27 3.75 +0.1 Pre-turning ⌀ Dmin = 10 mm × 1.16 – 10 % = 10.44 mm TX6 1.4 +0.05 TX30 4.2 +0.1 Pre-turning ⌀ Dmax = 10 mm × 1.16 – 1 % = 11.484 mm TX7 1.55 +0.07 TX40 5 +0.15 TX8 1.9 +0.1 TX45 5.8 +0.2 TX10 2.2 +0.1 TX50 6.7 +0.2 TX15 2.6 +0.1 TX55 8.2 +0.2 TX20 3 +0.1 TX60 9.8 +0.2 TX25 3.4 +0.1 Torx Plus® Hole Bore oversize Torx Plus® Hole Bore oversize ⌀ 0.00 – ⌀ 0.00 – mm mm mm mm mm mm IP6 1.5 + 0.1 IP20 3.2 + 0.1 IP8 2 + 0.1 IP25 3.6 + 0.1 IP10 2.3 + 0.1 IP30 4.5 + 0.1 IP15 2.7 + 0.1 IP40 5.4 + 0.15 The guide value of the hole depth t for a blind hole is: The guide value for the pre-turning length t is: t = desired profile depth × factor 1.5. t = desired profile length × factor 1.2 to 1.4. A counterbore of the bore facilitates centring of the broach A rear chamfer or an undercut promotes chip breaking. (countersink ⌀ ≙ the minimum external ⌀ of the profile). At larger bore diameters the bore contour remains slightly visible on the faces. A chamfer on the workpiece facilitates centring of the cutter insert. This does not cause any technical or qualitative restriction on the functionality of the profile. Hexagon Hexagon Hexagon Hexagon 10 10 10 10 2% 10 % 1% 29 ⌀10 ⌀10,2 ⌀11,484 ⌀10,44 Bore ⌀ min. Bore ⌀ max. Pre-turning ⌀ min. Pre-turning ⌀ max. Profile broaching process (tumbling) Concentric movement (tumbling) of the cutting edge quickly generates the desired profile in a single pass, with good process reliability. When machining on a CNC lathe, start at a low speed (n ≈ 100 rpm – 200 rpm) and high feed rate (f ≈ 0.1 mm/rev – 0.3 mm//rev). After a machining depth of approx. 0.5 mm, increase the feed rate and speed as shown in the table on page 922. Retract at a higher feed rate. Notes For maximum stability, always select the largest possible toolholder. Cooling lubrication is necessary – because of the small depth of the profile, external cooling is sufficient. 921