Please allow at least 4mm in your cutting allowance calculations for the width of the saw cut
We use table saws and horizontal band-saws, so edges will have a sawn finish
We only use sawing equipment, so we are unable to offer high precision items
Tolerances are +2mm to minus 0mm
We aim to cut as squarely as possible although incoming materials are sometimes out of square
We are unable to cut or machine shapes but we are happy to obtain a custom quotation for machined shapes or parts (please call us on 0114 2560889)
How to advise your sizes:
Please checkout your basket/cart
Fill in your details as usual on the checkout page
At section 5 of our checkout page, there's a "customer notes" box for you
Please enter your sizes and any notes for us there
Delrin Rod Tolerances
Manufacturers produce engineering plastics that are slightly oversize in either diameter and/or thickness.
This oversize tolerance, which is listed in the tables below, is provided to assist customers to produce very accurate items within the size shown and remove any minor surface imperfection.
Nominal Diameter
Tolerance in mm
4
+0.1 to +0.3
5 - 6
+0.1 to +0.4
8 - 10
+0.1 to +0.5
12 - 14 - 16 - 18 - 20
+0.2 to +0.7
22 - 25 - 28 - 30
+0.2 to +0.9
32 - 36 - 40
+0.2 to +1.1
45 - 50 - 56
+0.3 to +1.3
60 - 65 - 70
+0.3 to +1.6
75 - 80
+0.1 to +2.0
Nominal Diameter
Tolerance in mm
90
+0.5 to +2.22
100
+0.6 to +2.5
110
+0.7 to +3.0
120 - 125
+0.8 to +3.5
130 - 135 - 140
+0.9 to +3.8
150
+1.0 to +4.2
165 - 180
+1.2 to +5.0
200
+1.3 to +5.5
230 - 250
+1.5 to +6.2
Delrin Rod
Product Information
Product Full Identity:
Polyoxymethylene Homopolymer
Extruded Acetal H has higher mechanical strength, stiffness, hardness and creep resistance as well as a lower thermal expansion rate compared to Acetal C.
Properties
Better to machine than all Nylons
Low absorption and dimensional stability
10% better properties than Copolymer, Mechanically
This is the "Homo-Polymer" grade of Acetal and Delrin® is DuPont’s trade name for it. It has excellent load-bearing qualities in both tension and compression. It will absorb minimal amount of moisture and are resistant to a wide range of solvents. The service temperature range is -29º to 85º C, intermittent at 93.3º C. It has high yield strength at elevated temperatures. Properties include low friction (very slippy), high wear resistance and ease of fabrication.
Good abrasion resistance Good mechanical strength Low coefficient of friction Pretty good heat resistance Good electrical and dielectric properties Low water absorption
Susceptible to being attacked by both strong acids and oxidizing agents
Is not readily available in a flame-retardant grade
Typically very difficult to bond
Delrin® offers high tensile strength, stiffness, and creep resistance, and significantly outperforms many other polymers on impact resistance, allowing for thinner and lighter part design. In addition it offers outstanding low and high temperature performance, good colour ability, and good mating with metal and other polymers. It provides dimensional stability in high precision moulding and flexibility of design.
Typical applications include high performance engineering components (e.g. gear wheels, ski bindings, fasteners, crash pegs on motorcycles). It is also widely used in the automotive and consumer electronics industry.
In areas where very high wear is needed, it has very good resistance but there are better materials such as Nylon and UHMWPE. Areas where strong chemicals are around, this may be the job of its close relative The Co-Polymer Acetal.
Delrin® rod is excellent for machining using traditional methods such as turning, milling, drilling etc. The material is free-cutting, but does require sharp tools with a high clearance angle. It usually leaves little or no burrs. The use of soluble cutting lubricant is not necessary, but is recommended. Because the material lacks the rigidity of most metals, care should be taken to use light clamping forces and sufficient support for the work piece.
Machined Delrin® can be dimensionally unstable in comparison with metals, especially with parts that have large variations in wall thicknesses. It is recommended that such features are ‘designed-out’ e.g. by adding fillets or strengthening ribs. Annealing of pre-machined parts before final finishing is an alternative. A rule-of-thumb is that in general, small components machined in Delrin ® suffer from less warping.
Delrin ® is typically very difficult to bond. Special processes and treatments have been developed to improve bonding. Typically these processes involve surface etching, flame treatment or mechanical abrasion. Typical etching processes involve chromic acid at elevated temperatures. Once the surface is prepared, a number of adhesives can be used for bonding. These include epoxies, polyurethanes, and cyanoacrylates.
Epoxies have shown 150-500 psi shear strength on mechanically abraded surfaces and 500-1000 psi on chemically treated surfaces. Cyanoacrylates are useful for bonding to metal, leather, rubber and other plastics. Solvent welding is typically unsuccessful on it, this is due to its excellent solvent resistance.
Delrin® can be used to replace metal in automated food processing equipment, with the potential to produce lighter, lower-cost and corrosion-resistant components. Its low-friction properties make it an ideal material for improving the speed at which high-adhesion foods can be fed through a processor. It meets the U.S. FDA standards, is USDA approved, and is not UV stabilized.
Acetal resins are sensitive to acid hydrolysis and oxidation by agents such as mineral acids and chlorine. Delrin ® is also susceptible to alkaline attack and is more susceptible to degradation in hot water. Thus low levels of chlorine in potable water supplies (1–3 ppm) can be sufficient to cause stress corrosion cracking to develop, a problem which has been experienced in both the USA and Europe in domestic and commercial water supply systems.
Delrin ® is naturally opaque white, due to its high crystalline composition, but it is also available in black. Rods are available in diameters ranging from 10mm to 200mm.
Its a high performance, easily machine-able engineering plastic. Because of its high strength, slippery-ness and resistance to impact and fatigue, it is much more economical and easier to machine than most metals .
Basically there are two types of Acetal, Co-Polymer grade and Homo-Polymer grade. Delrin ® rod is the name usually given to the homo-polymer grade. Both grades are incredibly similar but have a few differences. Homo-polymer grade is generally used for more "mechanical/strength" applications, Co-Polymer grade works best in "chemical" applications. They are both engineering thermoplastics used in precision parts requiring high stiffness, low friction and excellent dimensional stability. Typical applications for injection-moulding include high performance engineering components such as small gear wheels, ski bindings, fasteners, knife handles, and automotive lock systems. This material is widely used in the automotive and consumer electronics industry. From auto parts to innovative new medical devices as well as most industrial solutions.