Ready Plastics

XX Phenolic Rod — Diameters, Lengths & Tolerances

XX phenolic rod is round bar stock produced from NEMA Grade XX paper phenolic laminate: layers of kraft paper impregnated with phenolic resin and compression-molded into rigid thermoset rod. Ready Plastics stocks XX phenolic rod as economical starting stock for switchboard components, terminal posts, panel hardware, and general electrical insulator blanks where consistent dielectric performance, lightweight construction, and low cost are the primary drivers. NEMA LI-1 governs Grade XX.

At a glance:

  • Diameter range: 0.125" to 4.0"
  • Standard length: 48" (4 ft) per piece
  • OD tolerance: typically ±0.010" on stock rod
  • Material: NEMA Grade XX — kraft-paper phenolic laminate (NEMA LI-1)
  • Production method: Compression-molded thermoset
  • Color: Natural tan to light brown

Standard Diameter Table

XX phenolic rod is stocked in the following standard diameters:

DiameterStandard LengthNotes
0.125" (1/8")48"Small insulator and pin stock
0.250" (1/4")48"Standoff and spacer blanks
0.500" (1/2")48"Terminal post and bushing stock
0.750" (3/4")48"General-purpose electrical insulator
1.000" (1")48"Panel hardware and connector stock
1.500" (1-1/2")48"Larger insulator blanks
2.000" (2")48"Heavy insulator rod stock
3.000" (3")48"Large-diameter panel component blanks

Cut-to-length is available on all diameters; minimum order is one piece.

Mechanical & Electrical Properties

XX phenolic rod carries the NEMA Grade XX property set per NEMA LI-1:

PropertyValue
Tensile strength35,000 psi (240 MPa)
Flexural strength (LW, 0.125")34,000 psi (230 MPa)
Compressive strength17,000 psi (115 MPa)
Shear strength11,500 psi (79 MPa)
Bond strength1,500 psi (10 MPa)
M-scale hardness120
Izod impact strength at 49 °C (LW)0.80 ft·lb/in
Specific gravity1.35
Water absorption (24 hr)2.00%
FlammabilityUL 94HB
Max. operating temperature280 °F (140 °C)

Note the notably high flexural strength (34,000 psi) and compressive strength (17,000 psi) for a paper-base grade — paper phenolic is stiffer in bending than cotton phenolic, though impact toughness is lower. The higher max. operating temperature of 280 °F (140 °C) also exceeds CE and LE ratings.

Typical Applications

  • Switchboard and control panel components — XX phenolic rod is the traditional material for low-voltage switchboard hardware including terminal posts, bus supports, and insulating pins
  • Panel instrument standoffs — Economical XX rod turns to precise standoff lengths for instrument panel mounting in control cabinets
  • Coil formers and bobbin blanks — Stiff paper-base construction and smooth lathe-turned OD support compact coil winding in relays and small transformers
  • Low-voltage terminal screws and bushings — XX rod threads and machines readily for hardware used in residential and light commercial panel assemblies
  • General-purpose insulator pins — Cost-effective round stock for non-critical insulating pin and peg applications throughout electrical equipment
  • Fixture and jig plugs — High compressive strength (17,000 psi) makes XX rod suitable for precision locating plugs in assembly tooling

Machining XX Phenolic Rod

XX phenolic rod machines readily on conventional lathes, mills, and drill presses using standard carbide-tipped tooling. The paper-base construction turns to a smooth finish with sharp tooling and moderate feed; threads tap cleanly without inserts for common hardware sizes. Cross-drilling is straightforward; moderate thrust and a backing block prevent exit delamination. XX produces fine abrasive dust during all machining — use dedicated dust extraction and respiratory protection.

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