Reference specs, per-sheet math, and router starting points for 1/2″ HDPE — cutting boards, marine and outdoor parts, jigs, and wear strips. Punch in your sheet price below for an instant per-part quote.
HDPE machines easily and doesn’t chip like acrylic, but it is soft and melts if the bit rubs. A single-flute O-flute bit with a high chipload and good chip clearing is the standard answer.
The catch is holding it down. Its slick surface defeats double-sided tape. Use clamps, screws into the spoilboard, or vacuum.
The same math the calculator above runs — worked out longhand, so you can sanity-check it against your own numbers.
On a router the kerf is the bit itself, 0.25″, and every part needs tabs or hold-down clearance, so plan for 18–20% scrap (Laguna puts well-nested shops at 82–92% sheet use).
This is the material line only. KraftyQuote’s router rows add the machine time with depth passes counted.
Published starting points, not settings to run blind. Hobby machines aren’t as stiff as the industrial machines tool makers chart for, so start at the hobby row and work up. Leave 0.015–0.020″ for a finish pass. On a hobby machine, slow the spindle rather than the feed. If it melts or goes gummy, the chipload is too small or the bit is dull.
A polished single-flute O-flute end mill. It leaves room for big chips and runs a high chipload; avoid 4-flute end mills, which pack and melt.
The bit is rubbing: chipload too small, a dull bit, or chips being recut. Feed faster or slow the spindle, ramp in instead of plunging, and blow or vacuum the chips clear.
HDPE has very low surface energy, so tape barely sticks. Clamp it, screw through waste areas into the spoilboard, or use vacuum hold-down.
HDPE expands about 0.0001" per inch per degree F. A 48" panel cut in a cold shop grows about 0.34" in a warm one, so cut and measure at the same temperature.
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