--- title: Alloy Selection for Tube Bending Wiper Dies description: Find out which alloys are recommended for tube bending wiper dies, understand the hardness and heat treatment requirements for AMPCO® M4 and AMPCO® 18.23, and learn the size limits for safe heat treatment. --- [Skip to content](https://academy.ampcometal.com/migration/en/knowledge/alloy-selection-tube-bending-wiper-dies#main-content) English Show submenu for translations ![logo-1.png\]](https://academy.ampcometal.com/hs-fs/hubfs/AMPCO%20CD%20elements/logo-1.png?height=40&name=logo-1.png) Open main navigation Close main navigation - English Show submenu for translations - Contact us Contact us Hello. How can we help you? - There are no suggestions because the search field is empty. 1. [Knowledge Hub](https://academy.ampcometal.com/migration/en/knowledge?hsLang=en) 2. [Application & Process Guidance](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en) 3. [Tube Bending & Forming](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#tube-bending-forming) # Alloy Selection for Tube Bending Wiper Dies ## Material Options, Hardness Considerations, and Heat Treatment Requirements Two alloy options are suitable for wiper dies in tube bending applications. AMPCO® M4 is the best performing material for this application. However, the hardness of the supplied material must be checked before use. If hardness exceeds 285 HBW, the tongue of the wiper die will be too hard and brittle, creating a risk of fracture. A special heat treatment process is available to bring hardness down to the required level where needed. AMPCO® 18.23 is the second option and is the most commonly selected grade. It offers performance close to AMPCO® M4 at a lower cost. A heat treatment process is also recommended for AMPCO® 18.23 to refine the grain structure and reduce the risk of cracking in the tongue area. This risk is particularly relevant when using AMPCO® 18 HCC material. For large wiper dies, the recommended maximum dimensions for heat treatment must be verified in advance. For bronze alloys with a section thickness exceeding 3 inches, the risk of cracking during heat treatment is elevated and should be assessed carefully before proceeding.   - [Fabrication & Processing](https://academy.ampcometal.com/migration/en/knowledge/fabrication-processing?hsLang=en#main-content) - [Forming & Bending](https://academy.ampcometal.com/migration/en/knowledge/fabrication-processing?hsLang=en#forming-bending) - [Welding & Joining](https://academy.ampcometal.com/migration/en/knowledge/fabrication-processing?hsLang=en#welding-joining) - [Cutting & Shearing](https://academy.ampcometal.com/migration/en/knowledge/fabrication-processing?hsLang=en#cutting-shearing) - [Application & Process Guidance](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#main-content) - [Lubrication & Surface Treatment](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#lubrication-surface-treatment) - [Thermoforming & Plastic Processing](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#thermoforming-plastic-processing) - [Oil, Gas & Chemical](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#oil-gas-chemical) - [Temperature & Thermal Limits](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#temperature-thermal-limits) - [Bearings & Wear Components](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#bearings-wear-components) - [Specialty & High-Demand Environments](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#specialty-high-demand-environments) - [Plastic Injection Molding](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#plastic-injection-molding) - [Metal Forming & Deep Drawing](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#metal-forming-deep-drawing) - [Tube Bending & Forming](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#tube-bending-forming) - [Resistance Welding](https://academy.ampcometal.com/migration/en/knowledge/application-process-guidance?hsLang=en#resistance-welding) - [Machining & Tooling](https://academy.ampcometal.com/migration/en/knowledge/machining-tooling?hsLang=en#main-content) - [Cutting Tool Selection](https://academy.ampcometal.com/migration/en/knowledge/machining-tooling?hsLang=en#cutting-tool-selection) - [Grinding & Surface Finishing](https://academy.ampcometal.com/migration/en/knowledge/machining-tooling?hsLang=en#grinding-surface-finishing) - [Materials & Coatings](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#main-content) - [Coating Properties & Selection](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#coating-properties-selection) - [Tribological Properties](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#tribological-properties) - [Thermal Properties](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#thermal-properties) - [Standards & Designations](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#standards-designations) - [Alloy Selection & Comparison](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#alloy-selection-comparison) - [Mechanical Properties](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#mechanical-properties) - [Physical & Electrical Properties](https://academy.ampcometal.com/migration/en/knowledge/materials-coatings?hsLang=en#physical-electrical-properties) - [Heat Treatment & Thermal Processing](https://academy.ampcometal.com/migration/en/knowledge/heat-treatment-thermal-processing?hsLang=en#main-content) - [Stress Relieving](https://academy.ampcometal.com/migration/en/knowledge/heat-treatment-thermal-processing?hsLang=en#stress-relieving) - [Grade Conversion & Heat Treatment Upgrades](https://academy.ampcometal.com/migration/en/knowledge/heat-treatment-thermal-processing?hsLang=en#grade-conversion-heat-treatment-upgrades) - [Supply Condition & Post-Delivery Processing](https://academy.ampcometal.com/migration/en/knowledge/heat-treatment-thermal-processing?hsLang=en#supply-condition-post-delivery-processing) [![Chill listening crop-3](https://academy.ampcometal.com/hs-fs/hubfs/AMPCO%20CD%20elements/logo-1.png?width=98&height=25&name=logo-1.png "Chill listening crop-3")](https://academy.ampcometal.com/knowledge?hsLang=en) ampcometal.com Help Center Copyright © 2026, AMPCO METAL S.A.