Gooseneck punches
Return-flange clearance, throat geometry, mounting interfaces and manufacturer-specific load limits for press-brake gooseneck punches.
Tags: tooling, sheet-metal, press-brakes, bending
On this page
KETEC lists 490 kN/m for its A47 gooseneck punch and 294 kN/m for A47-6. For a uniformly loaded 0.20 m bend, these correspond to 98.0 kN and 58.8 kN of nominal profile capacity. The catalog rates horn versions separately at 147 kN/m. Calculate the forming demand separately and check the entire moving flange envelope. KETEC, gooseneck and standard punches, pp. 19 and 30.
A gooseneck punch uses relief behind its tip to clear an existing return flange. Mate, American Precision Style punches
Clearance is a profile, not one number
| Feature | Meaning | What it does not establish |
|---|---|---|
| Throat or neck relief | Recessed region behind the punch tip | Clearance for every part orientation |
| Working height | Distance from a specified seating datum to the tip | Overall height including the mounting tang |
| Tip angle and radius | Local geometry at the bending contact | Final angle and radius after springback |
| Tool length | Extent along the bend line | Maximum return-flange depth |
A return flange occupies a moving envelope as the sheet rotates during bending. A profile that clears the final position can still interfere earlier in the stroke. The ram, clamp, die body and neighboring bends also occupy space. A single advertised throat depth therefore does not replace the complete tool cross-section and part geometry.
Bystronic's May 2019 tool-selection article illustrates a J-shaped part: when its small up-leg exceeds the bottom leg, the illustrated case needs a gooseneck; equal legs instead call for an offset acute punch. It relates these choices to workpiece interference and describes using tool drawings or bending simulation to evaluate it. These are rules for the shown geometry, not a universal flange-length formula. Bystronic, The rules of press brake tool selection, J-shape examples
Check bend order and tool orientation as well as throat depth. A different sequence or punch profile can change the moving envelope.
Relieved profiles have their own load limits
KETEC's Euro Style Press Brake Catalog, page 19, lists these full-size gooseneck profiles:
| Profile | Angle | Tip radius options | Listed maximum line load |
|---|---|---|---|
| A47 | 86° | 0.2 or 0.6 mm | 490 kN/m |
| A47-6 | 86° | 0.2 or 0.6 mm | 294 kN/m |
The catalog separately lists 147 kN/m for their horn versions. Its standard-punch K11.200 entry on page 30 lists 1,000 kN/m. These are profile-specific ratings, not an isolated shape comparison. KETEC, gooseneck and standard punches, pp. 19 and 30
The usual engineering tradeoff is between clearance and the section carrying the bending force. A relieved neck changes that load path relative to a straight punch. It is unsafe to infer an exact percentage reduction from the word “gooseneck”; material, heat treatment, tip, shoulder and profile all contribute. Tool-specific ratings provide the bounded evidence.
A line-load limit is force per loaded length, not the press's total tonnage. Punch, die, clamp and machine limits remain distinct; total press capacity does not override a weaker component. A short segment or horn can also have conditions different from a full-length tool.
Mounting and seating are separate from the bending profile
Mate's American Precision Style family illustrates one mounting system. Its Maglock magnets seat the punch shoulder in the holder and allow front loading with the described tang. Mate explicitly says this magnetic seating feature does not replace the holder's clamping system, which remains engaged during operation. These statements concern that family; a gooseneck outline alone does not identify an American, European or other mounting interface. Mate, Maglock seating and clamping distinction
As engineering synthesis, matching the tang, shoulder/load-bearing surfaces, retention arrangement and working-height datum is separate from obtaining part clearance. Adding an adapter or changing punch height changes the available opening and surrounding collision envelope. A nominal punch angle and radius cannot establish compatibility with a particular brake or clamp.
Worked example: line load versus total force
Original arithmetic using the cited ratings. Assume a uniformly loaded 0.20 m bend length:
A47: 490 kN/m × 0.20 m = 98.0 kN
A47-6: 294 kN/m × 0.20 m = 58.8 kN
The 39.2 kN difference assumes uniform loading of these profiles. It does not qualify horns or predict required forming force.
Coverage and source dates
Bystronic's article explicitly displays May 2019. No issue date is established for the Mate page or cited KETEC catalog; the latter's filename is not treated as an edition date. Sources were inspected on November 2, 2026.
This reference covers clearance and selected tooling examples. It does not establish universal throat dimensions, maximum flange height, punch tonnage, minimum bend radius, die opening or tooling interchangeability. The actual part envelope, forming method, material, support and mounting system remain application-specific. Manufacturer catalog entries do not establish a particular shop's installed or approved tooling.