Injection Molding Tolerance GuideInjection Molding Print Page - KUZMA Industrial Group

Dimensional Tolerances +/- mm

 Commercial TolerancePrecision Higher Cost
Dimension1 to 20
(+/-mm)
21 to 100
(+/-mm)
101 to 160
(+/-mm)
for each
20mm over
160 add
1 to 20
(+/-mm)
21 to 100
(+/-mm)
over 100
ABS0.1000.1500.3250.0800.0500.100
ABS/PC Blend0.1000.1500.3250.0800.0500.100
GPS0.0750.1500.3050.1000.0500.080
HDPE0.1250.1700.3750.1000.0750.110
LDPE0.1250.1700.3750.1000.0750.110
Mod PPO/PPE 0.1000.1500.3250.0800.0500.100
PA0.0750.1600.3100.0800.0300.130
PA 30% GF0.0600.1200.2400.0800.0300.100
PBT 30% GF0.0600.1200.2400.0800.0300.100project review
PC 0.0600.1200.2400.0800.0300.100required for all
PC 20% Glass 0.0500.1000.2000.0800.0300.080materials
PMMA 0.0750.1200.2500.0800.0500.070
POM0.0750.1600.3100.0800.0300.130
PP0.1250.1700.3750.1000.0750.110
PP 20% Talc0.1250.1700.3750.1000.0750.110
PPS 30%GF 0.0600.1200.2400.0800.0300.100
SAN0.1000.1500.3250.0800.0500.100

Straightness / Flatness Tolerances

Warpage is due to the difference between the mold shrinkage rates in the direction of the mold flow and across the flow. The efect is more noticable in fiber filled plastics. The major factor is different wall thickness as a thick section normally shrinks more than a thinner section. Mold design, gate position and process control can minimize this effect, however, the basic material behavior cannot be corrected 100%. Therefore a practical tolerance must be negotiated with the respective production units.
 Commercial TolerancePrecision Higher Cost
Dimensions0-100
(+/-mm)
101-160
(+/-mm)
0-100
(+/-mm)
101-160
(+/-mm)
ABS0.3800.8000.2500.500
ABS/PC Blend0.3800.8000.2500.500
Acetal0.3000.5000.1500.250
Acrylic0.1800.3300.1000.100
GPS0.2500.3800.1800.250
Mod PPO/PPE0.3800.8000.2500.250
PA0.3000.5000.1500.250
PA 30% GF0.1500.2000.0800.100
PBT 30% GF0.1500.2000.0800.100
PC 0.1500.2000.0800.100
Polycarbonate, 20% Glass0.1300.1800.0800.100
Polyethylene0.8501.5000.5000.850
Polypropylene0.8501.5000.5000.850
Polypropylene, 20% Talc0.8501.5000.5000.850
PPS 30%GF0.1500.2000.0800.100
SAN0.3800.8000.2500.500

Hole Diameter Tolerances +/- mm

 Commercial TolerancePrecision Higher Cost
Dimension0-3
(+/-mm)
3.1-6
(+/-mm)
6.1-14
(+/-mm)
14-40
(+/-mm)
0-3
(+/-mm)
3.1-6
(+/-mm)
6.1-14
(+/-mm)
14-40
(+/-mm)
ABS0.0500.0500.0800.1000.0300.0300.0500.050
ABS/PC0.0500.0500.0800.1000.0300.0300.0500.050
GPS0.0500.0500.0500.0900.0300.0300.0400.050
HDPE0.0500.0800.1000.1500.0300.0500.0500.080
LDPE0.0500.0800.1000.1500.0300.0500.0500.080
PA0.0500.0800.0800.1300.0300.0400.0500.080
PA30% GF0.0500.0500.0800.0800.0300.0400.0500.050
PBT30% GF0.0500.0500.0800.0800.0300.0400.0500.050
PC0.0500.0500.0800.0800.0300.0400.0500.050
PC 20% GF0.0500.0500.0800.0800.0300.0400.0500.050
PMMA0.0800.0800.1000.1300.0300.0500.0500.080
POM0.0500.0800.0800.1300.0300.0400.0500.080
PP0.0500.0800.1000.1500.0300.0500.0500.080
PP, 20% Talc0.0500.0800.1000.1500.0300.0500.0500.080
PPS 30%Glass0.0500.0500.0800.0800.0300.0400.0500.050
SAN0.0500.0500.0800.1000.0300.0300.0500.050

Blind Hole Depths Tolerances +/- mm

 Commercial TolerancePrecision Higher Cost
Dimension1-6
(+/-mm)
6.1-14
(+/-mm)
Over 14
(+/-mm)
1-6
(+/-mm)
6.1-14
(+/-mm)
Over 14
(+/-mm)
ABS0.0800.1000.1300.0500.0500.080
ABS/PC Blend0.0800.1000.1300.0500.0500.080
GPS0.0900.1000.1300.0500.0500.080
HDPE0.1000.1200.1500.0500.0800.100
LDPE0.1000.1200.1500.0500.0800.100
PA0.1000.1000.1300.0500.0800.100
PA, 30% GF0.0500.0800.1000.0500.0500.080
PBT, 30% GF0.0500.0800.1000.0500.0500.080
PC, 20% GF0.0500.0800.1000.0500.0500.080
PMMA0.1000.1000.1300.0500.0800.100
Polycarbonate0.0500.0800.1000.0500.0500.080
POM0.1000.1000.1300.0500.0800.100
PP0.1000.1200.1500.0500.0800.100
PP, 20% Talc0.1000.1200.1500.0500.0800.100
PPO/PPE000800.1000.1300.0500.0500.080
PPS, 30% GF0.0500.0800.1000.0500.0500.080
SAN0.0800.1000.1300.0500.0500.080

Concentricity/Ovality Tolerances +/- mm

 Commercial TolerancePrecision Higher Cost
Dimensionup to 100
(+/-mm)
up to 100
(+/-mm)
ABS0.2300.130
ABS/PC Blend0.2300.130
GPS0.2500.150
HDPE0.2500.150
LDPE0.2500.150
PA0.2500.150
PA, 30% GF0.1500.100
PBT, 30% GF0.1500.100
PC0.1300.080
PC, 20% GF0.1300.080
PMMA0.2500.150
POM0.2500.150
PP0.2500.150
PP, 20% Talc0.2500.150
PPO/PPE0.2300.130
PPS, 30% GF0.1300.080
SAN0.2300.130

Please note that the real achievable tolerances for injection molding are very dependent on the design. This document serves as a guide only.
KUZMA Industrial Group cannot be held legally liable for the tolerances given in this document.