Acetal is a crystalline engineering polymer that is formed by polymerzing anhydrous formaldehyde in order to form an oxymethlylene chain.

Acetal is a strong material that provides good dimensional stability along with a low coefficient of friction.

The material provides good all around resistance to different chemicals types. It has excellent resistance to substances like oils, alcohols and formaldehydes as well as good protection to methylenthylketons. Acetal will only offer limited resistance to solvents if used for a short time and has poor resistance to acids.

Acetal is suitable for machining and is also quite easy to process. It is normally used for applications such as plates, spring, gears, pulleys, sheaves as well as bushings and housings.

Acetal is a formaldehyde based material, as such care should be taken when processing it as any formaldehyde released can irritate skin and eyes.


Mechanical Properties of Acetal

Flexural Modulus (MPa)
Tensile Strength


Elastic Modulus (MPa)
Compressive Strength (MPa) 
at yield or break
Flexural Strength (MPa) 
at yield or break
Elongation at break (%)

Rockwell M

2553 – 3105

(23 ºC)

57 - 72
3105 (compressive)

( at 10% strain)

15 - 75
75 - 90


Thermal Properties of Acetal

Coef of Thermal Expansion (10-6/ºC)
Deflection Temperature (ºC) at 0.46 MPa
Thermal Conductivity (W/m-ºC)
61 - 110
85 - 121


Physical & Electrical Properties of Acetal

Specific Gravity
Water Absorption (% weight increase)
Dielectric Strength (V/mil); 
1/8" thick specimen unless noted
0.2 - 0.22 (24 hrs)
500 (90 mil thick)
0.65 - 0.8 (saturated)