ABS Plastic Grades — GP, ABS-FR, ABS-FR2 & Royalite

ABS plastic is not a single material — it's a family of grades with meaningfully different performance profiles. Choosing the wrong grade means either overpaying for properties you don't need or failing a flame-spread test in a UL-listed enclosure. This guide breaks down each commercial ABS grade, what distinguishes it, and which applications it's designed for.

At a Glance

• ABS (GP): General-purpose, HB flame rating, lowest cost, widest color availability
• ABS-FR: UL94 V-0 flame retardant — required for regulated electrical enclosures
• ABS-FR2: Second-generation FR formulation — improved impact retention vs. first-gen FR additive systems
• Royalite: Impact-modified, textured surface, transit and automotive specification material
• ABS-PC Blend: Improved heat resistance and impact vs. straight ABS — a step toward polycarbonate properties at lower cost
• Grade selection driver: Flame rating requirement is the primary branch point; surface/aesthetics drives the secondary choice

Grade Comparison Table

ABS (General Purpose)

General-purpose ABS is the baseline material — the grade that most people mean when they say "ABS sheet." It is manufactured by extrusion and targeted at the widest range of thermoforming, machining, and fabrication applications where a UL94 flame rating is not required.

Key Characteristics

• HB (horizontal burn) flame rating — lowest UL94 class; the material burns slowly but does not self-extinguish in the UL94 test
• Full color range: natural (off-white), black, white, and custom sheet colors available in most thicknesses
• Widest size range: 0.030 in through 1.0 in thickness, both 4×8 ft and 5×10 ft sheet

Where to Specify GP ABS

Use general-purpose ABS for: machined enclosures and housings not requiring UL listing, thermoformed trays and packaging, signage substrates, prototype panels, and retail display components. If there is any chance the design will need a UL flame rating, switch to ABS-FR upfront — retrofitting FR grade into a qualified assembly restart flame testing.

ABS-FR (Flame Retardant, UL94 V-0)

ABS-FR incorporates a flame-retardant additive system — typically bromine-based in traditional formulations, phosphorus-based or mineral-filled in non-halogenated versions — that causes the burning polymer to char and self-extinguish rather than sustain a flame.

UL94 V-0 What It Means in Practice

In the UL94 V-0 test, five test bars are each exposed to a flame twice for 10 seconds. Each bar must extinguish within 10 seconds after each flame removal; no flaming drips are permitted; total burn time across all specimens cannot exceed 50 seconds. This is a significantly more demanding standard than HB (horizontal burn) where the material simply has to burn slowly.

For electrical enclosures, control panels, and equipment housings under:

• UL 508A (industrial control panels)
• UL 60950-1 / 62368-1 (IT and AV equipment)
• IEC 60695-11-10 (equivalent international test)
• IEC 62368-1 (audio/video, IT equipment)

…V-0 is either required or strongly preferred. ABS-FR is the right choice for these applications.

Tradeoffs vs. GP ABS

Flame-retardant additives typically reduce impact toughness somewhat — ABS-FR Izod values run 4–5 ft-lb/in vs. 6 ft-lb/in for GP. For most enclosure panel applications, the structural loading is low enough that this reduction is not limiting. Color range is narrower (primarily black and white); custom colors require minimum order quantities.

ABS-FR2 (Second-Generation Flame Retardant)

ABS-FR2 is a reformulated flame-retardant grade developed to address the impact toughness penalty of first-generation ABS-FR. By using a different FR additive system — often non-halogenated phosphorus compounds or intumescent packages — formulators can recover some or all of the impact resistance lost in ABS-FR while maintaining V-0 performance.

When to Choose FR2 Over FR

Specify ABS-FR2 when:

• The enclosure design includes thin-wall sections, snap fits, or features that concentrate stress
• Impact requirements are higher (product is handled roughly or subject to drop events)
• Your compliance program is moving toward halogen-free materials (EU REACH, RoHS, ELV considerations)
• The application requires V-0 at thinner gauge than first-gen ABS-FR supports

FR2 stock availability is narrower than standard ABS-FR — typically black sheet only in a limited thickness range. Plan lead times accordingly.

Royalite (Impact-Modified, Textured ABS)

Royalite is an impact-modified ABS-based sheet product with a distinctive matte textured surface. Originally developed for transit interior applications by Sparton (later acquired by multiple owners; the Royalite brand remains the generic descriptor for this category), it is specified throughout rail, bus, aviation cabin, and automotive interior systems.

What Makes Royalite Different

The rubber content of Royalite is significantly higher than standard ABS — notched Izod values of 7–12 ft-lb/in are typical, compared to 6 ft-lb/in for GP ABS. The extruded-in texture (typically a fine-grain matte) eliminates the need for painting in trim applications, reducing cost and adding durability (texture hides minor scratches that would be visible on a smooth painted surface).

Transit and Automotive Specifications

Royalite is tested to and frequently certified against:

• ASTM E-162 (surface flammability index) for transit vehicles
• ASTM E-662 (smoke density) for transit and aviation
• FMVSS 302 (automotive interior flammability)
• FAR 25.853 (aircraft cabin interior flammability) — in specific formulations

Confirm the specific test certifications available from your supplier for the lot you are ordering. Not all Royalite sheet in stock carries all certifications.

Colors and Sizes

Royalite ships in black, charcoal gray, and gray-beige. Custom colors require large minimum orders. Standard sheet sizes are 4×8 ft and 5×10 ft; thicknesses from 0.060 in to 0.250 in cover the range of transit interior panel applications.

ABS-PC Blend (Polycarbonate/ABS Alloy)

PC/ABS blends combine the heat resistance and impact strength of polycarbonate with the processability and surface aesthetics of ABS. The result is a material that exceeds standard ABS in nearly every structural property category while remaining easier to process than straight polycarbonate.

Property Improvements Over ABS

• Continuous use temperature: 200–220°F vs. 160°F for ABS
• Izod impact: 9–13 ft-lb/in vs. 6 ft-lb/in
• Tensile strength: 6,000–7,500 psi vs. 5,000 psi
• Flame rating: Many PC/ABS blends achieve UL94 V-0 without separate FR additives

Where PC/ABS Is the Right Upgrade

Automotive interior components requiring better thermal stability (dash panels exposed to solar heating, underhood-adjacent brackets), electronics housings in higher-temperature environments (industrial controls in warm enclosures), and medical device housings requiring autoclave resistance sometimes upgrade to PC/ABS from standard ABS.

The cost premium over straight ABS is 30–60%. Compare to full polycarbonate sheet when evaluating; if optical clarity or very high impact resistance is needed, the ABS portion of the blend may not be worth the property tradeoffs vs. straight PC. The ABS vs. Polycarbonate comparison page details these tradeoffs.

Grade Selection Guide

Related Guides

More related guides

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

Industries

• Automotive

Compare to other materials

• Polycarbonate Vs. Abs
• Acrylic Vs. Abs
• Pvc Vs. Abs

Frequently asked questions — Abs FAQ