ThePipingMart Blog Grades P5 Tool Steel (UNS T51605) – Composition, Properties and Uses

P5 Tool Steel (UNS T51605) – Composition, Properties and Uses

Tool Steel P5

Tool steel is a type of steel designed to be used in manufacturing tools, such as cutting and shaping. Tool steel comes in wide varieties, one of the more popular types being P5 Tool Steel . In this blog post, we’ll discuss the uses, corrosion resistance, heat resistance, heat treatment process, machining capabilities, and welding characteristics of UNS T51605.

P5 Tool Steel Composition

Element Content (%)
Fe 95
C 0.1
Mn 0.20-0.60
Si 0.4
Cr 2.00-2.50
Ni 0.35
Cu 0.25
P 0.03
S 0.03

P5 Tool Steel Physical Properties

Properties Metric Imperial
Density 7.85 g/cm3 0.281 lb/in3

P5 Tool Steel Mechanical Properties

Properties Metric Imperial
Poisson’s ratio 0.27-0.30 0.27-0.30
Elastic modulus 190-210 GPa 27557-30458 ksi

P5 Tool Steel Equivalent

  • ASTM A681
  • UNS T51605

P5 Tool Steel Uses

Tool Steel P5 is an air-hardening tool steel that provides good wear resistance and toughness for a range of applications. It can be used in various automotive, aerospace and energy industries. This type of tool, steel, is often used for making dies, punches and other cutting tools because it is able to withstand high-impact forces without losing its shape or breaking. It can also be used for making moulds and jigs due to its low carbon content, which helps with machinability.

Corrosion Resistance

Tool Steel P5 has excellent corrosion resistance due to its chromium content which helps to protect against rusting and wear. However, it should still be stored properly when not in use to avoid exposing it to moisture or other corrosive elements that could damage the material over time.

Heat Resistance

Tool Steel P5 has good heat resistance, which makes it suitable for applications where exposure to higher temperatures may occur. It can be heated up to temperatures between 1120°F-1475°F (600°C-800°C) before losing its strength or becoming brittle. Its maximum operating temperature should not exceed 1120°F (600°C).

Heat Treatment

The heat treatment process for Tool Steel P5 involves slowly heating the material up until it reaches a temperature between 1120°F-1475°F (600°C-800°C), then quickly cooling down using either water or oil quenchants depending on the desired hardness level desired for the final product. It is important to note that if too much time is spent at higher temperatures, there will be an increase in the risk of cracking or warping during the cooling down process, so individual temperatures should be closely monitored throughout this process.


Tool Steel P5 can be machined easily, but care must be taken when doing so, as excessive strain on the material could lead to deformation or breakage if handled improperly. It is best suited for use with high-speed turning tools and drill bits made from cobalt-based alloys as these are more resistant to wear than regular carbon steel options would be when working with this type of tool steel.


While welding can be done with tool steels such as Tool Steel P5, their ability to withstand high temperatures without warping or breaking limits what types can successfully weld onto them without causing damage due to thermal expansion or contraction during the welding process itself. Therefore it is recommended that only gas tungsten arc welding (GTAW) processes are used when attempting any welding on this material due to its ability to maintain consistent weld pool depth during operation, which helps minimize the risk associated with thermal expansion & contraction caused by welds cooling down at different rates after completion.


In conclusion, Tool Steel P5 has numerous uses across a variety of industries thanks to its unique combination of properties such as good corrosion resistance, heat resistance & machinability, along with other characteristics that make it suitable for multiple applications ranging from cutting tools & dies through moulds & jigs while also offering decent weldability when proper techniques are followed by experienced professionals familiar with working with this type material. This makes it the perfect choice for those looking to create durable parts components capable of performing under extreme conditions while maintaining optimal performance levels over long periods despite potential environmental factors they may be exposed to throughout their lifespan.

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