UHMW Machining Services

Q: Is UHMW machining difficult?

It cuts easily but is hard to hold accurately. UHMW is soft and springy, distorts under clamping and expands eight times more than steel, so tolerances depend on fixturing, sharp tooling and measurement at a known temperature rather than on the cutter.

Q: What tolerance is realistic for machined UHMW parts?

±0.01 mm on small, well-supported features such as bushing bores; ±0.05 mm on large plates and guides, and ±0.1 mm on parts over 1 m. We state the inspection temperature on the report because a 1 m guide moves 0.2 mm per degree.

Q: UHMW or HDPE: which should I specify?

UHMW for anything that slides, wears or takes impact: guides, wear strips, star wheels. HDPE for tanks, fittings, gaskets, cutting boards and welded assemblies where stiffness, weldability and cost matter more than abrasion life.

Q: Is polyethylene machining suitable for food-contact parts?

Yes. Natural virgin UHMW and HDPE are FDA and EU 10/2011 compliant, absorb no water and machine to a sealed surface that resists bacterial growth. Reprocessed black or colored grades are for non-food use.

DEK's UHMW machining turns UHMW-PE and HDPE sheet, rod and block into wear strips, chain guides and star wheels, holding ±0.01 mm on small features. Sharp tooling and low-force fixturing keep soft, springy PE flat after cutting.

Get A Quote View All Plastics

±0.01 mm
Small Features
3–5 days
Prototype Lead Time
No MOQ
1 to 10,000+ Pieces

Three black machined plastic fittings on white

ISO 9001:2015 Certified AS9100D and ISO 13485 certified

What Sets UHMW Machining and HDPE Machining Apart

Polyethylene is the lowest-friction, most abrasion-resistant commodity plastic, absorbs no water and is FDA compliant in natural grades. We machine UHMW-PE and HDPE as part of our plastic CNC machining services.

PE is also soft, springy and expands 150–200 µm/m·K, so it distorts under clamping and moves after cutting more than any other plastic we run. We cut it on the same 3-, 4- and 5-axis mills as stainless and aluminum, with a realistic ±0.05 mm on large parts.

Machining plastics beside metals since 2002
ISO 9001:2015, ISO 13485 and AS9100D
Engineer-reviewed quote within 6 hours
IQC, IPQC, FAI and OQC at 23 °C

Black polyethylene fitting with threaded end

Polyethylene Grades We Machine

Four polyethylene grade families cover food-contact wear parts, low-cost liners, unlubricated slides and welded HDPE components.

UHMW-PE natural/virgin
FDA compliant
For FDA-compliant wear strips, chain guides, star wheels and food processing components. See UHMW-PE.
UHMW-PE reprocessed
Black or green, lower cost
For non-food wear parts, liner plates, truck bed and hopper liners where virgin material is not required and cost matters.
UHMW oil-filled
30–50% lower friction
Oil-filled and dry-lubricant UHMW grades for slides and guides running where lubrication is impossible.
HDPE natural / colored
0.95 g/cm³
For cutting boards, tank fittings, gaskets, machined covers and marine components. See HDPE.
UHMW-PE
0.10–0.20 friction on steel
40 MPa ultimate and 21 MPa yield tensile strength, 0.93 g/cm³, 80 °C max continuous service, water absorption below 0.01% in 24 h.
HDPE
25–30 MPa tensile
Friction of 0.20–0.25 dry on steel, 80 °C max service; slightly stiffer and cleaner-cutting than UHMW, with the same 150–200 × 10⁻⁶/K expansion.

CNC milling HDPE block with curly plastic chips

±0.05 mm
Realistic on large parts
500 mm
Max turning diameter
3 m
Long guide profiling
Ra 0.8–1.6
As-machined finish, µm

How DEK Approaches UHMW CNC Machining

PE cuts easily but is hard to hold accurately, so every process is built around sharp tooling, low clamping force and measurement at 23 °C.

1

CNC Milling

3-, 4- and 5-axis CNC milling for wear strips, chain and belt guides, liner plates, star wheels and machine guards.
2

CNC Turning

CNC turning for rollers, sheaves, bushings and sprockets up to 500 mm diameter, holding ±0.01 mm on short turned diameters.
3

Long Guide Profiling

Guides up to 3 m are profiled with sectional fixturing so the strip lies flat; long parts rest between roughing and finishing. See large part machining.
4

Drilling and Tapping

Drilling, counterboring and tapping with sharp high-helix drills; countersunk pockets are standard on wear strips.

Design & Machining Tips for Polyethylene

What our engineers check on every PE drawing before quoting, so tolerances stay achievable on soft, high-expansion parts.

1

Expansion and Clamping

PE expands eight times more than steel: specify 23 °C and slotted mounting holes on a 2 m guide. We use vacuum fixtures or soft jaws and measure after unclamping.
2

Sharp Tooling

Dull edges push and tear UHMW, leaving fuzz and dimensional drift. We use polished high-rake carbide, high spindle speeds and air blast.
3

Skin Stress in Thick Plate

Extruded and compression-molded plate bows when one face is machined. We rough both sides, rest the blank, then finish; annealing at 80 °C helps parts over 50 mm thick.
4

Tolerances by Part Size

±0.01 mm on small supported features, ±0.05 mm on large parts, ±0.1 mm on parts over 1 m. Tolerance the running surface and mounting holes, not free edges.
5

Thin Walls

Keep walls at 1.5 mm minimum on UHMW and 1.0 mm on HDPE; thinner walls deflect from the cutter and come out tapered.
6

Threads and Fasteners

Tapped PE threads strip easily: specify countersunk through-bolts with washers or press-in metal inserts, with 0.3 mm clearance for expansion.

When to Choose UHMW vs HDPE, Nylon or Delrin

How UHMW-PE compares with HDPE and other bearing plastics. Where load and heat exceed PE, 304 stainless carries a replaceable UHMW wear strip.

Criteria	This MaterialUHMW-PE	HDPE	Nylon	Delrin
Choose it for	Wear strips	Tanks, fittings	Loaded gears	Precision parts
Abrasion	10x HDPE	Lower	–	Lower
Friction	0.10–0.20	0.20–0.25	Higher	–
Water uptake	< 0.01%	< 0.01%	Absorbs	–
Max temp	80 °C	80 °C	100 °C	–
Stiffness	Soft, springy	Stiffer	–	Far stiffer
Cost	Low	Cheaper	–	Higher

Where Machined Polyethylene Parts Are Used

Low friction, abrasion resistance and zero water absorption put PE wherever parts slide, wear or stay wet.

Food Processing & Packaging

Conveyor wear strips, chain guides, star wheels, timing screws and cutting boards machined in FDA-compliant UHMW.

Wear Strips Star Wheels Timing Screws
Industrial, Farm & Mining

Slide pads, belt guides, sprockets, chute and hopper liners and bumper blocks for industrial equipment, agriculture and mining.

Slide Pads Hopper Liners Bumper Blocks
Marine & Construction

Dock fenders, rub rails, pump wear rings, HDPE tank fittings and outrigger pads for marine, water treatment and construction.

Dock Fenders Rub Rails Outrigger Pads

Finishing Options for Machined Polyethylene

CNC machining + finish for PE parts. Vapor polishing, anodizing and plating do not apply to polyethylene.

PE Finishes

As-machined
Bead blasting
Laser marking
Hot-gas welding

Need a colored part instead of paint? Ask our engineers.

UHMW Machining FAQ

Common questions from engineers specifying UHMW and HDPE parts.

Is UHMW machining difficult?

It cuts easily but is hard to hold accurately. UHMW is soft and springy, distorts under clamping and expands eight times more than steel, so tolerances depend on fixturing, sharp tooling and measurement at a known temperature rather than on the cutter.

What tolerance is realistic for machined UHMW parts?

±0.01 mm on small, well-supported features such as bushing bores; ±0.05 mm on large plates and guides, and ±0.1 mm on parts over 1 m. We state the inspection temperature on the report because a 1 m guide moves 0.2 mm per degree.

UHMW or HDPE: which should I specify?

UHMW for anything that slides, wears or takes impact: guides, wear strips, star wheels. HDPE for tanks, fittings, gaskets, cutting boards and welded assemblies where stiffness, weldability and cost matter more than abrasion life.

Is polyethylene machining suitable for food-contact parts?

Yes. Natural virgin UHMW and HDPE are FDA and EU 10/2011 compliant, absorb no water and machine to a sealed surface that resists bacterial growth. Reprocessed black or colored grades are for non-food use.