On a press brake, specialty punches are chosen for the part geometry, not for the badge on the machine. Three common jobs drive most specialty punch questions:

First pick the type for the bend. Then confirm it mounts on your clamp system—use the compatibility checklist and browse the Press Brake Tooling catalog filters (Radius tooling, Flattening tools, Press brake punches). This article is application selection among punch types. It is not a system-compatibility deep dive, not a reliability buyer guide, and not a SKU dump of the full catalog.

Radius punches / radius tooling: when the inside radius is the product

A radius punch (or changeable radius tool on a holder) presents a curved tip so the sheet forms around a known radius instead of a sharp knife edge. Shops reach for them when:

• The drawing calls out a minimum inside radius larger than a sharp punch will produce
• Cosmetic marking or cracking risk rises with a sharp tip on the chosen material
• You need repeatable radius across sections (segmented radius tools on a shared holder)

What to watch (no invented formulas):

• Match the tool radius to the drawing, not to a rule of thumb invented in a blog
• Radius choice interacts with V-opening, material, and tonnage—verify against the tooling manufacturer’s data and a test bend
• Some Tranyond radius tools are changeable inserts on a mounting set (holder), not a one-piece punch forever fixed at one R

Verified store examples (illustrations only):

• Radius tools such as 10.181 Radius-tools R 3.0 through 10.188 Radius-tools R 6.5 (listed under Radius tooling; material called out as C45 on PDP copy)
• Holders such as 40.002 Mounting set for radius tools type I and 40.003 Mounting set for radius tools R 3.0–6.5 (PDP notes changeable / sectionalized radius-tool use)

Browse the live filter: Radius tooling.

Definition Radius tooling on a press brake is upper tooling whose working tip is radiused (or carries a radiused insert) so the formed inside radius is controlled by the tool geometry rather than by a sharp punch tip alone.

Flattening tools: when the edge must finish flat

A flattening tool (or flattening insert / flattening die set, depending on the system) is used when the job needs a flattened hem or closed edge—not when you only need a larger inside radius.

Typical pattern at a high level (always follow your machine/tooling procedure and risk assessment):

1. Form the open hem or pre-bend with appropriate punch/die geometry
2. Flatten / close with the flattening tool set
3. Inspect for cracks, springback, and mark-off before production rate

What to watch:

• Flattening is often a second operation, not a substitute for the first bend punch
• Confirm whether you need a flattening insert, a dedicated flattening tool, or a system-specific flattening die—Tranyond lists several under Flattening tools
• Working length of the set must cover the hem length; do not assume one insert length fits every bed

Verified store examples:

• 40.500 Flattening insert — PDP lists flattening insert; lengths such as 835 mm / 415 mm appear on the page; “delivered as a complete set”
• 10.325 Flattening-tool — height listed 17.0 mm, material C45 on PDP description

Browse: Flattening tools.

Definition A flattening tool is press-brake tooling used to close or flatten a pre-formed hem/edge. It is selected for the finishing step, not as a generic replacement for a standard acute punch.

Window / closed-box punches (including Rotax® listings): when the return hits the tool

Closed boxes and deep return flanges often collide with a standard straight or even a common gooseneck profile. A window punch (also described on Tranyond PDPs as a window punch/top-tool for closed boxes, with some models carrying the store name Rotax®) opens clearance in the tool body so the already-formed side can pass while you bend the next flange.

Use this family when:

• Side returns or box walls hit a standard punch body
• You need a punch angle suited to the sequence (examples on live PDPs include 85° and 86° window punches)
• Segmented lengths must clear corners without swapping to a custom one-off every time

What to watch:

• Window geometry is about clearance and sequence, not about creating radius or flattening by itself
• Tip radius and angle on the PDP still matter for the bend quality
• System family still matters—e.g. listings exist for different TYD-System lines

Verified store examples:

• 40.690 — 86° Window punch/top-tool for closed boxes "Rotax®" — height 220 mm, tip radius listed R 1.0 mm, TYD-System Trumpf on PDP
• 40.680 — 85° Window punch/top-tool for closed boxes "Rotax®" — height 110 mm, tip radius listed R 0.8 mm, TYD-System Amada on PDP

Find more under Press brake punches on the tooling collection (window/Rotax models appear in that punch listing). Definition A window / closed-box punch is an upper tool with a relieved “window” in the body so return flanges or box sides can clear the tool during multi-bend sequences. On Tranyond, some of these are sold under the Rotax® product naming on the PDP.

Quick decision: which punch type?

Ask the drawing three questions:

1. Is the inside radius the requirement? → Start with radius tooling (and the correct holder if inserts are used).
2. Must the edge finish flat / hemmed? → Plan a flattening step with the right insert or flattening tool.
3. Will a formed side collide with a normal punch? → Look at window / closed-box (Rotax®) punches for clearance.

If the answer is “sharp air bend, open profile, no hem, no box collision,” a standard acute/gooseneck punch may be enough—this article will not expand that catalog.

One tool rarely replaces another: a radius insert does not flatten a hem; a flattening set does not create box clearance; a window punch does not automatically give you a specified large radius.

After the type is chosen: confirm fit, then browse

1. Lock the punch type from the part geometry (table above).
2. Confirm clamp / system compatibility before ordering: How to Confirm Press Brake Tooling Compatibility.
3. Open the catalog hub and use the real filters: Press Brake Tooling & Compatibility → Radius tooling / Flattening tools / Press brake punches (and system filters as needed).
4. Check PDP height, angle, radius, material, and working length against the setup.
5. Complex drawings or mixed sequences → Contact Us with machine model, clamp photos, and the part print.

Related (different jobs): How to Choose Reliable Press Brake Tooling for quality/tonnage/supplier checks; Magnetic Squaring Arm for blank orientation on the die—not punch-type selection.

FAQ

What is a radius punch on a press brake? Upper tooling with a radiused tip (or a radiused insert on a holder) used to control the formed inside radius and related cosmetics, instead of relying on a sharp punch tip alone.

When do I need a flattening tool instead of a standard punch? When the process needs a flattened hem or closed edge after a pre-bend. A standard acute punch forms; a flattening tool finishes the flat.

What is a window punch / closed-box punch? A punch with body clearance so return flanges or box sides can pass during later bends. Tranyond lists examples as window punches for closed boxes, including models named Rotax® on the PDP. Can one punch do radius and flattening? Not as a general rule. Radius tooling and flattening tools solve different outcomes. Use the type that matches each step—and confirm each tool’s mounting system.

After I pick the punch type, how do I confirm it fits my machine? Run the clamp/system checklist, then match the PDP to your interface (or ask Tranyond with model + photo/drawing). Start here: compatibility guide and the tooling catalog.

Soft CTA

Match the punch to the job geometry first—radius, flattening, or window/closed-box—then confirm the clamp system and pick the live SKU from the tooling catalog. If the print has mixed returns, hems, and radius callouts, send the drawing via Contact Us before you order the wrong specialty tip.