Plastic Stock Forms — Sheet, Rod, Tube, Bar, Film & Custom Parts

Plastic stock is sold in standard forms — sheet, round rod, tube, hex bar, square bar, film, and tape — and machined or fabricated into custom parts. The form you specify determines which materials are available, what sizes are stocked, what tolerances are achievable, and how the material is processed (extruded, cast, or compression-molded). Each guide below covers the standard size range, material availability, tolerances, and the applications that drive demand for that form.

If you know the form you need, go directly to that guide for stocked dimensions and materials. If you're still deciding between machined stock and fabricated parts, the last two guides explain when each approach applies.

Raw Stock — Cut to Size

Plastic Sheet Stock

The most versatile form. Sheet stock spans 1/32″ to 4″ thick across all thermoplastic and thermoset families — from 0.030″ PTFE skived film to 3″ PEEK compression-molded plate. The sheet guide covers:

• Standard sheet sizes: 24″ × 48″, 24″ × 96″, and 48″ × 96″ nominal; some materials available in 48″ × 120″
• Thickness range by material: commodity polyolefins from 1/8″ to 2″; engineering grades from 1/16″ to 3″; thermosets from 1/32″ to 2″
• Tolerances: extruded sheet ±10% on thickness typical; cast and compression-molded sheet ±5%; skived PTFE to ±0.005″
• Cutting methods: table saw, band saw, router, waterjet, CNC mill — material-specific guidance included

Materials commonly stocked as sheet: UHMW, HDPE, LDPE, polypropylene, PVC, ABS, acetal, nylon, polycarbonate, acrylic, PETG, PEEK, Ultem, PPS, polysulfone, PVDF, PTFE, G10 and FR4, and all phenolic grades.

Plastic Rod Stock

Round rod from 1/8″ to 12″ diameter. The rod guide covers extruded, cast, and compression-molded rod forms:

• Extruded rod: the most common form, available in a wide range of engineering and commodity grades. Typical diameter range 1/8″ to 4″ for most materials; larger diameters in select grades.
• Cast rod: used for large-diameter nylon (up to 12″ and larger by custom pour), PTFE (compression-molded), and some phenolic grades. Cast rod has lower internal stress than extruded.
• Diameter tolerances: extruded rod typically +0.000″/−0.015″ to −0.060″ depending on diameter; cast rod looser.
• Length: standard 4-foot and 6-foot lengths; cut-to-length available.

Rod is the starting point for machined bushings, bearings, spacers, and turned parts on a lathe. Materials available as rod include all 28 stocked grades except LDPE (sheet only) and some thermoset formats.

Plastic Tube Stock

Extruded and cast tube for bushings, sleeves, and pre-formed bearing stock. Tube reduces material removal and machining time compared to boring from solid rod.

• Size range: OD from 1/4″ to 12″ depending on material and wall; wall thickness from 1/16″ to 2″
• Tolerances: OD and ID tolerances vary by material and process — tighter on PEEK and acetal tube than on commodity grades
• Common materials as tube: acetal, nylon, PEEK, PTFE, UHMW, polycarbonate, acrylic, G10 and FR4, cotton phenolic, linen phenolic
• Applications: pre-formed bushing blanks, sleeve bearings, pipe lining, and protective sleeving

Tube is specified by OD × ID or OD × wall. The guide includes a wall-thickness selection table for bushing applications based on shaft diameter and load class.

Plastic Hex Bar

Hexagonal bar in nylon, acetal, and select engineering plastics. Hex bar cuts machining time when turning threaded parts, standoffs, or hex-profile hardware.

• Across-flats sizes: 1/4″ to 3″ AF for most grades
• Common materials: acetal (Delrin), nylon 6 and 6/6, PEEK, polycarbonate, PTFE, polypropylene
• Length: 4-foot standard; cut-to-length available
• Applications: custom nuts, spacers, standoffs, threaded fittings, and valve bodies that require a wrench flat

Hex bar replaces the step of milling flats on turned rod, which saves time and reduces material waste for high-volume machined hardware.

Plastic Square Bar

Square bar stock for keys, slides, and machined bar parts where a square cross-section reduces setup time.

• Size range: 1/4″ to 4″ square
• Common materials: acetal, nylon, UHMW, polycarbonate, PEEK
• Length: 4-foot standard
• Applications: key stock, slide rails, fixture components, and machined guides where square geometry is required

Square bar is less commonly stocked than rod or sheet; availability by material is confirmed on the form page. Many applications that would use square bar can alternatively be cut from sheet with the same lead time.

Plastic Film & Tape

Thin-gauge sheet, skived film, and pressure-sensitive tape for low-thickness applications where standard sheet is too thick or rigid.

• Skived PTFE film: 0.001″ to 0.060″ thick; 6″ to 48″ wide. Skived (peeled) from a compression-molded billet — more consistent than extruded at thin gauges. Used for seals, gaskets, liner wraps, and bearing strips.
• UHMW tape (PSA-backed): 1/32″ to 1/4″ thick; self-adhesive backing for field-applied wear liners. Eliminates machined fastener holes in liner applications.
• PTFE tape: thread sealing and anti-stick tape in various widths and thicknesses
• HDPE and LDPE film: thicknesses from 0.003″ up; used for vapor barriers, liners, and packaging
• Tolerances: skived film to ±0.002″; tape to ±0.005″

Film and tape are the right choice when you need a liner or seal surface without machining — adhesive-backed UHMW tape in particular is widely used for conveyor guide-rail refurbishment.

Custom Parts

Custom Machined Plastic Parts

CNC-machined parts from sheet, rod, and tube stock — prototype quantities through production runs. Machined parts cover:

• Operations: turning, milling, drilling, tapping, boring, contouring, and grinding
• Tolerances: ±0.005″ typical for most engineering plastics; ±0.002″ achievable on stable materials (acetal, PEEK, G10 and FR4) with proper fixturing
• Material range: all 28 stocked materials; machined from whichever form provides the most efficient blank
• Finishes: as-machined, vapor-polished (acrylic/PC), or hand-polished to print
• Typical parts: bushings, spacers, gears, manifolds, valve seats, wear plates, insulators, and fixtures

The guide covers material-specific machining parameters (speeds, feeds, tool geometry, coolant), fixturing considerations, and how to specify tolerances that are achievable in plastic without over-constraining the machining process.

Fabricated Plastic Parts

Welded, formed, and bonded plastic fabrications for tanks, hoods, ducts, enclosures, and assemblies that cannot be machined from solid stock.

• Hot-gas welding: polypropylene, PVC, PVDF, HDPE, UHMW — structural welds with joint strengths to 80% of base material
• Thermobending / hot-line bending: polycarbonate, acrylic, PETG — sheet bent to angle without loss of transparency
• Solvent bonding: acrylic, polycarbonate, ABS — clear or opaque structural bonds
• Mechanical fastening: all materials — through-bolt, insert, or clip fastening details covered
• Applications: chemical tanks, acid baths, fume hoods, safety enclosures, ductwork, and trays

Fabricated parts are the right choice for larger assemblies (tanks over 12 gallons, custom housings, ductwork runs) where machining from solid is impractical. The guide covers design-for-fabrication rules — wall thickness minimums, weld joint access, and corner radii by material.

Choosing the Right Form