Introduction

Polyamide is one of the most widely specified engineering plastic families in industrial manufacturing. When sourcing polyamide semi-finished products, two grades consistently appear in procurement specifications: PA6C (Polyamide 6 Cast) and PA6.6 (Polyamide 6.6). While both belong to the polyamide family, they are manufactured differently and perform differently across key technical parameters.

This article explains the differences between PA6C and PA6.6, when to specify each grade and what forms are available from Plastix Factory.

What is PA6C?

PA6C is produced through a pressureless casting process using caprolactam as the raw material. The casting process allows for a wide range of shapes and large dimensions including round bars up to 2100mm diameter, making it the preferred choice for large industrial components.

PA6C is a universal engineering plastic with high mechanical strength, sufficient toughness and very good machinability. Its properties can be further optimised through the addition of lubricants, stabilisers and reinforcing agents across eight available variants.

What is PA6.6?

PA6.6 is produced through an extrusion process and offers slightly higher surface hardness and rigidity than PA6C, with reduced moisture absorption and increased wear and heat resistance. However it has lower toughness compared to PA6C.

PA6.6 is widely specified across mechanical engineering, aircraft construction, electrical appliance industry, automobile industry and equipment manufacturing applications where high strength, rigidity and heat resistance are required.

PA6C vs PA6.6: Key Technical Comparison

When to Specify PA6C

Large Diameter Components The casting process used to produce PA6C allows for round bars and tubes up to 2100mm diameter. For large pulleys, rope sheaves, bearings and gear wheels where large cross-sections are required, PA6C is the only viable polyamide option.

Modified Material Properties PA6C is available in eight variants allowing precise material optimisation for specific applications. PA6C OL incorporates liquid lubricant for dry-running sliding elements. PA6C Powerglide combines the antifriction properties of PE 1000 with the wear resistance of polyamide. PA6C Heat offers thermal aging stabilisation for elevated temperature applications.

Universal Mechanical Engineering Applications For general structural parts in plant and mechanical engineering including pulleys, bearings, rope sheaves and gear wheels, PA6C Natural offers the best combination of performance and value.

When to Specify PA6.6

Higher Heat Resistance Requirements PA6.6 has a higher continuous service temperature than PA6C, making it the preferred choice for components operating in elevated temperature environments such as under-bonnet automotive applications and electrical appliance components.

Reduced Moisture Sensitivity PA6.6 absorbs less moisture than PA6C, making it more dimensionally stable in varying humidity conditions. For precision components where dimensional stability across changing environmental conditions is critical, PA6.6 is the better choice.

Glass Fibre Reinforced Applications PA6.6 GF30, reinforced with 30 percent glass fibre, offers increased dimensional stability, very high rigidity and greater heat resistance than unreinforced grades. It is specified for structural applications in aircraft construction, automobile manufacturing and equipment manufacturing where maximum stiffness is required.

Aircraft and Automotive Applications PA6.6 is widely specified in aircraft construction and the automobile industry due to its higher heat resistance, rigidity and reduced moisture absorption compared to PA6C.

Available Variants

PA6C Variants at Plastix Factory Plastix Factory supplies eight PA6C variants: Natural ivory, MO Black with molybdenum sulphides, Colour in red yellow green and blue, MoS2 anthracite black, OL with liquid lubricant, Wax modified grey, Powerglide green and Heat stabilised blue, plus High Impact in natural and yellow.

PA6.6 Variants at Plastix Factory Plastix Factory supplies PA6.6 in natural colour and PA6.6 GF30 in black, reinforced with 30 percent glass fibre for enhanced rigidity and heat resistance.

Available Forms

PA6C is available as sheets, round bars, tubes, rings, blocks and discs up to 2100mm diameter. Standard sheet formats are 2000x1000mm and 3050x1220mm with thicknesses from 5mm to 120mm.

PA6.6 is available as sheets and round bars. Sheets are supplied in 3000x610mm format with thicknesses from 8mm to 100mm. Round bars are available from 2mm to 250mm diameter in 3000mm lengths.

Both materials are available as CNC-machined finished parts manufactured to customer drawings through Plastix Factory in-house CNC centres.

Summary: Which Should You Choose?

Choose PA6C when your application requires large diameter components, specific tribological properties through material modification, universal mechanical engineering parts or cost-effective general purpose polyamide stock shapes.

Choose PA6.6 when your application requires higher heat resistance, reduced moisture absorption, glass fibre reinforced rigidity or compliance with automotive and aerospace industry material specifications.

Request a Quote

Plastix Factory supplies both PA6C and PA6.6 in standard stock dimensions and custom formats from four global production facilities in Austria, Germany, South Korea and the United Arab Emirates. All production is certified to ISO 9001:2015 and ISO 14001:2015.

Contact our technical team or visit our B2B portal at plastixfactory.com/store to place your order.