Canvas Phenolic Specifications — Sheet, Rod & Tube Sizes

Canvas phenolic is stocked in three primary forms — sheet, rod, and tube — each governed by ASTM D709 (Standard Specification for Laminated Thermosetting Materials) and NEMA LI 1-1998. These standards define not only the electrical and mechanical property thresholds that a material must pass to carry a grade designation, but also the dimensional tolerance bands within which finished stock is expected to fall. This page documents standard stocked sizes, applicable tolerances, and the governing specification references buyers need to cite on procurement documents.

At a Glance

• Governing standards: ASTM D709, NEMA LI 1-1998
• Grades covered: C (structural), CE (oil-impregnated bearing)
• Forms: sheet, rod, tube
• Thickness/diameter range: sheet 1/8"–4"; rod 1/2"–6"; tube 1"–8" OD
• Standard panel sizes: 36"×48" and 48"×96"
• Standard lengths (rod/tube): 48" nominal; some diameters available in 72"
• Color: natural brown

Governing Standards and Grade Designations

ASTM D709

ASTM D709 is the primary dimensional and material specification for industrial-grade laminated thermosetting products. It classifies laminates by:

• Type: thermoset resin system (phenolic, epoxy, melamine, etc.)
• Grade: reinforcement and impregnant (maps to NEMA designations)
• Form: sheet, rod, tube

For canvas phenolic, the relevant ASTM D709 designations are:

When writing purchase specifications or engineering drawings, cite both standards for completeness: "Canvas phenolic, ASTM D709 Grade C [or CE], NEMA LI 1 Grade C [or CE]." This eliminates ambiguity between suppliers.

NEMA LI 1-1998

NEMA LI 1 sets minimum property values that a laminate must achieve under standard test conditions to qualify for a given grade designation. For Grade C canvas phenolic, the minimum mechanical properties are:

Note that NEMA specifies minimums — actual production stock from quality suppliers typically exceeds these floors, particularly on impact (commonly 6.5–8.0 ft-lb/in in practice).

Sheet Specifications

Standard Panel Sizes

Thickness Range and Tolerances

Width and Length Tolerances

For 48"×96" panels, ASTM D709 width and length tolerances are +3/16" / −0". Panels are produced slightly oversized and cut to customer requirement. Custom-cut pieces carry a standard ±1/16" cut tolerance.

Rod Specifications

Canvas phenolic rod is manufactured by center winding fabric-impregnated sheets on a mandrel, then pressing and curing under heat. This produces a concentrically wound cylinder with the canvas weave running helically around the rod axis — providing good in-plane properties and reasonable isotropic cross-sectional behavior.

Standard Diameters and Tolerances

Rod is supplied with an OD tolerance that is always positive — rod is cut slightly oversized relative to the nominal so that the customer can turn to final size. The bore for a finished bushing is created by drilling and boring from solid rod.

Straightness

Rod straightness per ASTM D709: maximum 0.010" total indicator runout (TIR) per linear foot for diameters up to 2"; 0.015" per foot for larger diameters. Select shorter cut lengths when straightness is critical.

Tube Specifications

Pre-formed tube stock eliminates the drilling step for bushing and sleeve applications. Canvas phenolic tube is typically produced by mandrel winding or by pressing around a cylindrical form.

Standard Tube Sizes

Tube OD tolerances: +0.030" / −0.000" for OD up to 4"; +0.050" / −0.000" for larger sizes. ID tolerances: +0.000" / −0.030" for bores up to 3"; ±0.030" for larger bores — bore typically requires finish boring to final specification.

Ordering Information

Grade Identification

Specify the NEMA grade explicitly on all purchase orders and drawings:

• Structural use: Canvas Phenolic — NEMA Grade C / ASTM D709 Grade C
• Bearing/bushing use: Canvas Phenolic — NEMA Grade CE / ASTM D709 Grade CE

Lead Times

Standard diameters and thicknesses ship from stock at most distributors. Non-standard thicknesses (e.g., 2-3/4"), odd diameters, and Grade CE in larger sizes may require 2–4 weeks lead time. Confirm availability before committing to a project schedule.

For machining parameters and tooling recommendations for these stock sizes, see the machining guide. For application-specific grade selection, visit grades or the main canvas phenolic hub.

Compare these size ranges with what is available in cotton phenolic and linen phenolic to select the best starting stock for your application.

Related Guides

More related guides

Cross-cluster suggestions to help shoppers and engineers explore adjacent topics:

Compare to other materials

• Cotton Vs. Canvas Phenolic
• Linen Vs. Canvas Phenolic