Views: 0 Author: Site Editor Publish Time: 2025-09-15 Origin: Site
Acrylic (PMMA) might look like glass but behaves like a fussy roommate when you try to mill it: it melts, chips, and sometimes cracks if you don’t pick tools and settings that respect its quirks. That’s why “one-size-fits-all” end mills (designed for steel or hardwood) usually give poor edges, chatter, or melted surfaces on acrylic. This guide walks you through the best manufacturers that make end mills (and related tooling) specifically engineered to cut acrylic cleanly — plus how to choose, run, and finish the parts.
Acrylic (polymethyl methacrylate) is a transparent thermoplastic used in signage, displays, lenses, and housings. It is softer than metals, but it responds to heat very differently from wood: too much friction → melting and smearing; too aggressive feed → cracking or chipout. So geometry, flute polishing and chip evacuation matter more than brute strength.
Think of acrylic like sugar glass: fast, clean, and brittle if pushed wrong. Metal cutters remove chips that quickly cool; acrylic needs cutters that make large, continuous chips and evacuate heat. That’s why toolmakers produce single-flute or O-flute geometries and polished flutes for acrylic — details we’ll cover below.
Single-flute and O-flute geometries are the rockstars for acrylic. They offer large flute valleys (excellent chip evacuation) and a sharp rake to slice rather than rub. O-flute versions are especially popular for deep slotting and sign work because they clear long chips without clogging.
Two- and three-flute cutters can be used for finishing passes or when you need a slightly stiffer cutter for longer reach — but they typically require higher spindle speeds and careful chip load management to avoid melting.
Polished flutes, coatings, and why finish matters
Polished flutes and uncoated carbide are common for acrylic because smooth flutes reduce built-up edge and help the chip slide out. Some specialty cutters are finished/polished specifically for transparent acrylic to reduce micro-scratches on cut faces.
— Single flute = great chip volume; O-flute = best for deep routing; 2–3 flutes = finishing or when rigidity is needed.
— High helix (45–55°) can improve finish on walls and pockets in non-ferrous and plastics, but single/O-flutes often have geometry tailored for thermoplastics.
Use the shortest, stiffest tool that meets your reach. Micro end mills (1/16"–1/8") need very high spindle speeds to maintain surface speed; longer lengths amplify deflection and chatter which ruin acrylic finish.
DATRON offers dedicated solid carbide acrylic milling cutters — from single-flute to form cutters — and emphasizes polished flutes for transparent plastics. Their product literature and application notes specifically recommend single-flute, polished cutters for smooth, crystal-clear finishes in acrylic sign and display work.
Amana Tool markets a popular line of aluminum & acrylic end mills (55° helix designs) targeted at signmaking and non-ferrous/plastic work. Their geometry aims for excellent finishes on acrylic walls and pocket floors — a common choice for CNC sign shops and makers.
LMT Onsrud (often just Onsrud) builds a large catalog of O-flute and single flute end mills designed to cut acrylic and similar non-ferrous materials. Their “O-flute for deep slotting” and single-flute profiles are widely used in sign and routing operations because they resist gumming and keep edges clean.
Harvey Tool (Harvey Performance) offers a “End Mills for Plastics” lineup with single-flute, two-flute and special high-relief geometries. Their guides walk you through flute selection for different plastics and stress polished flutes and reduced helix options for reduced lifting forces.
OSG produces end mills and has guidance on cutting resins and super engineering plastics. They offer advanced geometries tuned for resin processing that are useful where clarity and edge quality matter (uncoated carbide with sharp rake, polished flute finishes). OSG’s technical notes discuss how end mills for acrylic are often uncoated with strong rake to achieve sharpness.
Guhring is a global end-mill maker with premium carbide capability and a broad line that includes tools optimized for plastics and composites (PCD and uncoated geometries for composite plastics). If you want high-quality substrate and global supply, Guhring is worth a look. (See their plastics/composites categories for detail.)
Micro 100 offers material-specific end mills for plastics & composites. Their single-flute router end mills and diamond-cut flute patterns aim to reduce BUE (built-up edge) and improve chip evacuation — useful for acrylic prototypes and production.
Sandvik Coromant offers composite and plastics tooling (CoroMill Plura, etc.) built for production environments. While often sold into aerospace and automotive composites, those router geometries scale to industrial acrylic applications where consistency and process control are important.
Kyocera produces small, precise PCB and plexiglass tools — micro end mills and routers designed for very small diameters and clean edges. If you’re milling thin plexiglass sheets or fine micro-features, Kyocera’s PCB/micro tooling lines are highly relevant.
Ruiyu is known for universal performance end mills and specialty profiles. While they’re not an “acrylic-only” brand, their high-quality solid carbide and router style cutters are chosen for jobs that need stiffness and repeatability.
