How resistant are materials to the effects of chemicals? Our tables provide guideline values for this.
When plastics and chemicals come into contact, they will usually exert an influence on each other. Questions involving the resistance to chemicals of polymer materials are severely simplified by statements like “resistant” “conditionally resistant” or “not resistant”. In reality, there are highly complex causal connections involved here. Realistic tests are therefore always necessary in order to eliminate uncertainties as far as humanly possible. The influencing factors involved in determining the resistance to chemicals include the exposure time to and concentration of the contact chemical, temperature, stress levels in the workpiece, ageing, exposure to cleaning agents or energy-rich radiation.
Here you find (arranged by materials) further information on resistance to chemicals:
No legal entitlement can be derived from these particulars; we do not accept any warranty or liability. Resistance to chemicals and mechanical strength alone do not suffice for assessing whether a product is fit for purpose.
The tolerances of the semi-finished products in our stock merchandise are based on the currently valid standards.
Following DIN norms are being used for semi-finished materials:
Rods, sheets, hollow rods: DIN-Norm (DIN EN 15860)
Welding rods: According to DVS 2211
Tight tolerance stipulations
If you should need different (plastic-friendly) tolerances, please talk to us. We will then check the relevant options individually.
Machining the various thermoplastics to make semi-finished products will always cause internal stresses. These can be reduced by a subsequent thermal treatment step (annealing). Since at each step in machining the stress level in the component is increased, which under unfavorable circumstances may lead to distortion of the component concerned, we recommend incorporating an additional intermediate annealing step for components with close tolerance specifications.
All the products listed on the GEHR website are stock articles with the standard lengths available. On request, in response to a specific inquiry, customised items can be produced in a minimum quantity.
All weights specified are based on average production weights. As a rule these are the invoiced weights, only High Performance Materials will partially be invoiced by actual weight.
GEHR makes no representations or warranties regarding the technical statements in this brochure.
Desired capability characteristics are only binding if there is an explicit agreement when the contract is concluded.
Modifications concerning the support of technical progress will be reserved. Values are dependent on the diameters and can deviate.