PLA vs PETG vs ABS Strength Comparison: Tensile, Impact, and Layer Adhesion

Why This Comparison Matters

PLA, PETG, and ABS are the three most widely printed beginner-to-intermediate filaments, but their strength profiles are radically different. Choosing the wrong one for a bracket, enclosure clip, or functional part means a print that fails in service — not at the slicer. This article uses measured data from real TDS sheets across 813 filaments to give you concrete numbers rather than vague guidance.

Tensile Strength: Which Filament Pulls the Hardest?

Tensile strength (MPa) measures how much pull-force a material withstands before breaking. It's the primary property for parts under sustained load — hooks, hangers, structural clips, and any joint under tension.

Across our database, PETG edges out PLA on tensile strength at the median: Prusament PETG measures 47 MPa, and Prusament PLA measures 51 MPa — with Prusament's PLA actually beating their PETG, which illustrates how much brand and grade variation matters. At the population level:

• PLA: median 45 MPa, range 10–120 MPa across 280 filaments
• PETG: median 48 MPa, range 22–105 MPa across 110 filaments
• ABS: median 42 MPa, range 15.7–460 MPa across 73 filaments

The ABS max of 460 MPa (FormFutura EasyFil ABS) is a clear outlier — the median of 42 MPa is more representative of what you'll get from a standard spool. Standard PLA+ from eSUN PLA+ at 63 MPa and colorFabb PLA Economy at 59.6 MPa both outperform the median ABS grade. Meanwhile, top PETG grades like Fiberlogy PETG+CF (105 MPa) and Polymaker PolyCore PETG-1113 (100.3 MPa) significantly outpace standard filaments.

Practical takeaway: All three materials are within a competitive range at their median. The brand and grade you pick matters more than the material family. Upgrading from a generic $15/kg PLA to a quality PLA+ can yield more tensile strength than switching to ABS.

Impact Strength: Which Filament Survives Drops?

Impact strength (kJ/m² Charpy or notched Izod equivalent) measures energy absorbed before fracture. This is critical for enclosures, protective covers, drone frames, and any part that takes sudden loads rather than sustained tension.

Here ABS clearly separates from the pack. Across 48 filaments with impact data, ABS delivers a median of 19 kJ/m² — compared to PLA's median of 13 kJ/m² across 223 filaments and PETG's median of 9 kJ/m² across 76 filaments.

Notable impact performers in our database:

• Bambu Lab PLA Tough+: 80.6 kJ/m² — a formulated "tough PLA" grade that competes with ABS
• Bambu Lab ABS: 39.3 kJ/m² — a typical premium ABS
• eSUN ABS+: 42 kJ/m² — higher than the median, with good elongation at 30%
• Fillamentum ABS Extrafill: 24 kJ/m²
• Polymaker PolyMax PLA: 38.9 kJ/m² — another toughened PLA formulation that rivals standard ABS

The wide spread within each family is significant. The 75th percentile of PLA impact strength is 27.3 kJ/m² — higher than the ABS median. Toughened PLA+ and impact-modified PLA grades have effectively closed the gap with standard ABS on impact resistance. However, if you need reliable impact performance without seeking out specialty grades, ABS remains the safer default.

Flexural Strength and Stiffness: Bending Under Load

Flexural strength (MPa) is how much bending force a material resists before permanent deformation. Flexural modulus (MPa) measures stiffness — how much a part resists bending at all. High stiffness is good for precise mechanical parts; lower stiffness matters for snap-fits and living hinges.

Our database shows:

• PLA: flexural strength median 73 MPa (223 filaments), modulus median 2,640 MPa (214 filaments)
• PETG: flexural strength median 70 MPa (81 filaments), modulus median 2,000 MPa (76 filaments)
• ABS: flexural strength median 66 MPa (63 filaments), modulus median 2,300 MPa (58 filaments)

PLA is the stiffest of the three — its median flexural modulus of 2,640 MPa exceeds ABS (2,300 MPa) and PETG (2,000 MPa). In practice, PLA parts feel the most rigid and dimensionally stable under light loads. colorFabb PLA/PHA reaches 90.4 MPa flexural strength; eSUN PLA-Basic hits 101.2 MPa. Among PETG, colorFabb XT-CF20 achieves 110 MPa flexural strength.

The trade-off: PLA's stiffness also makes it more brittle. It snaps rather than bending, which is why its elongation at break (median 8%) is similar to ABS (median 8%) but both are far below PETG (median 9.3%, with some grades exceeding 100% — Fillamentum PETG stretches to 120% before breaking).

Layer Adhesion: The Real-World Strength Factor

No database property is labeled "layer adhesion," but two material properties directly predict inter-layer bond strength in FDM prints:

1. Elongation at break — materials that stretch rather than snap tend to form better inter-layer bonds because they flow more during deposition
2. Print temperature range — higher print temps generally improve layer fusion

On elongation at break:

• PETG: median 9.3% (range 1.8–400%, many grades above 30–100%) — the widest spread, best overall flexibility
• ABS: median 8% (range 0.7–45%) — moderate elongation, decent layer fusion at high temps
• PLA: median 8% (range 0.5–580%) — similar median to ABS, but most standard PLAs cluster at 5–12%

In practice, PETG is widely regarded as having the best layer adhesion of the three for FDM printing. Its semi-crystalline structure and higher elongation allow it to form dense inter-layer bonds. ABS layers bond well at 230–250°C print temperatures but require an enclosure to prevent differential cooling (warping). PLA bonds adequately but its relatively low print temp (typically 190–220°C) means less thermal energy available for fusion.

Heat Resistance: Where ABS Wins Decisively

For parts exposed to elevated temperatures — outdoor use, car interiors, dishwashers, electronics enclosures — heat deflection temperature (HDT) is the critical spec. The gaps here are much larger than the strength differences:

• PLA: median HDT 55°C (range 45–137°C, 226 filaments) — will deform in a hot car (60–80°C dashboard)
• PETG: median HDT 70°C (range 58–100°C, 90 filaments) — borderline for summer car interiors
• ABS: median HDT 88°C (range 65–105°C, 68 filaments) — comfortably handles most automotive and appliance environments

ABS's 33°C advantage in HDT over PLA is more practically significant than any tensile strength difference between the three. Bambu Lab ABS has an HDT of 84°C; Polymaker PolyCore ABS-5022 reaches 102°C. Standard PLA at 55°C HDT is a genuine liability outdoors in summer.

Side-by-Side Comparison

Here are the key mechanical differences at a glance — based on median values across our database:

When to Use Each Material

Choose PLA When:

• The part stays indoors and below 50°C — PLA's 55°C HDT leaves very little margin
• You need maximum dimensional accuracy and stiffness — its flexural modulus (median 2,640 MPa) is the highest of the three
• Print failure tolerance is low and you want the most forgiving material — PLA rarely warps at standard room temperature
• Budget matters — PLA is typically the cheapest of the three

Best PLA for strength: eSUN PLA-Basic (63.95 MPa tensile, 101.2 MPa flexural) and Prusament PLA (51 MPa tensile, 83 MPa flexural, 55°C HDT) are strong reference points.

Choose PETG When:

• The part needs some flexibility — PETG's elongation at break can exceed 100% in some grades vs 8% median for PLA and ABS
• Moisture or chemical resistance matters — PETG resists humidity better than both PLA and ABS
• You need slightly better heat resistance than PLA without the warping risk of ABS — PETG's 70°C HDT handles most indoor warm environments
• Layer adhesion is critical — PETG typically bonds inter-layer seams more completely than PLA

Best PETG for strength: Prusament PETG (47 MPa tensile, 68°C HDT) and colorFabb nGen (54 MPa tensile, 63°C HDT) are reliable standard grades. For structural performance, Polymaker PolyCore PETG-1113 at 100.3 MPa tensile and 78°C HDT is a standout.

Choose ABS When:

• The part will experience impacts, drops, or sudden load — ABS's median 19 kJ/m² impact strength is 46% higher than PLA
• Operating temperature exceeds 60°C — ABS's median 88°C HDT is essential for automotive, appliance, and outdoor applications
• Post-processing matters — ABS can be acetone-smoothed for watertight, polished surfaces that PETG and PLA cannot match
• You can print in an enclosure — ABS requires contained heat to prevent warping on large parts

Best ABS for strength: eSUN ABS+ (40 MPa tensile, 42 kJ/m² impact, 73°C HDT) balances toughness with printability. Fillamentum ABS Extrafill (39 MPa tensile, 24 kJ/m² impact, 81°C HDT) is a premium choice with consistent quality.

The Grade Effect: PLA+ and ABS+ Close the Gap

The "vs" framing somewhat obscures how much variation exists within each family. Consider:

• Bambu Lab PLA Tough+ delivers 80.6 kJ/m² impact strength — more than 4× the PLA median and well above all standard ABS grades in our database
• Polymaker PolyMax PLA reaches 38.9 kJ/m² impact — competitive with many ABS filaments
• PLA's tensile strength p75 is 53 MPa — meaning 25% of PLA filaments already outperform the PETG median

If you specifically need impact toughness but want to avoid ABS's printing challenges, toughened PLA+ grades are a legitimate alternative for parts that stay under 55°C.