NEMA XXX-PC

NEMA XXX-PC is the cold-punch paper phenolic grade — a resin formulation that allows clean punching and blanking at room temperature, eliminating the pre-heating step required by NEMA XXX-P while maintaining the electrical insulation properties of the XXX family.

TL;DR

Chemistry & Reinforcement

NEMA XXX-PC achieves cold-punch capability through a combination of:

• Reinforcement: Alpha-cellulose kraft paper (same as XXX and XXX-P)
• Resin: Phenolic resin compounded with plasticizers and impact modifiers selected for room-temperature ductility without sacrificing the cure completeness needed for electrical performance
• Color: Dark brown
• Density: ~1.30–1.34 g/cc

The plasticizer package in XXX-PC is heavier than in XXX-P, which provides more toughness at room temperature. The trade-off is that overall rigidity and maximum service temperature are modestly lower than standard XXX. The cellulose reinforcement tears cleanly under punch-press dies when the resin matrix has sufficient toughness, rather than shattering or delaminating as a fully-cured brittle phenolic would.

Key Properties

Typical Applications

XXX-PC is selected when cold-punch press capability is already established in a plant and adding an oven or infrared pre-heater for XXX-P is impractical:

• Terminal boards (cold-press lines) — same end use as XXX-P, but on unheated presses.
• Insulating gaskets and washers — punched from sheet in high-volume blanking operations; common in appliance and motor manufacturing.
• Bus bar insulation shields — punched U-shapes and L-shapes that slip over bus bar conductors in 600V-class panels.
• Barrier strips and dividers — punched slot-and-tab insulation barriers in low-voltage switchgear compartments.
• Phenolic relay bases — blanked base plates with multiple contact holes for relay socket mounting.

Standard Sizes

Note: XXX-PC is predominantly a sheet-form product. Rod and tube in this specific grade are uncommon — for rod or tube applications, standard XXX or XX is more readily sourced.

Standards Reference

1. NEMA LI 1 — Grade XXX-PC properties table specifies minimum dielectric strength, maximum water absorption, and punch qualification. NEMA LI 1-2020 is current.
2. MIL-I-24768/16 — Military equivalent, Type PBECP (Paper-Base, Electrical, Cold-Punch). QPL certification for defense programs.
3. ASTM D709 — master test standard for laminated thermosetting materials; punch evaluation methods referenced in NEMA LI 1.

Comparison to Neighbor Grades

Choose XXX-PC when: your production line is set up for cold-press punching and you want to avoid the oven step of XXX-P. Choose XXX-P when your press is hot and the same die runs XXX-P on an existing heated tooling layout. Choose XXX for one-off, CNC-routed, or machined parts where punching speed is irrelevant.

More related guides

Other paper phenolic grades

• NEMA XX Mechanical Grade
• NEMA XXX Electrical Grade
• NEMA XXX-P Post-Formable

Electrical insulation upgrades

• Canvas Phenolic CE Grade
• Linen Phenolic LE Grade

All grades index

• NEMA Grades Directory