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Cast-In Heater Specifications and Tolerances

Cast-In Thermal component Specifications and Tolerances

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Casting Alloys

Casting Alloy	Aluminum	Copper	Silicone	Zinc	Lead	Maximum Iron	Tin	Other
Aluminum 319	85.8 - 91.58%	3.0 - 4.0%	5.50 - 6.50%	≤ 1.0%	—	≤ 1.0%	—	≤1.7%
Aluminum 356	90.1 - 93.3 %	≤0.25%	6.50 - 7.50%	≤0.35%	—	≤0.60%	—	≤1.125%
Bronze	9.0 - 11.0%	≥ 86.0%	—	—	—	0.80 - 1.50%	—	≤1%
Yellow Brass	≤0.55%	58.0 - 64.0%	≤0.05%	32.0 - 40.0%	0.80 - 1.50%	≤0.70%	0.50 - 1.50%	≤1%

Material Properties

Material	Classification	Max. Surface Temperature	Density	Coefficient of Linear Thermal Expansion	Specific Heat Capacity	Thermal Conductivity	Melting Point
		°F (°C)	(lb/in³)	(in/in/°F × 10-6)	(BTU/lb-°F)	(BTU-in/hr-ft²-°F)	(°F)
Aluminum 319	Aluminum 319.0	700 (371)	0.101	12.7 @ 68° – 572°F	0.23	754	960 – 1120
Aluminum 356	Aluminum 356.0	750 (399)	0.0968	12.9 @ 68° – 572°F	0.23	1160	1030 – 1140
Bronze	UNS C95300	1350 (732)	0.272	9 @ 68° – 572°F	0.0896	437	1900 – 1913
Yellow Brass	UNS C85700	1200 (649)	0.304	12.2 @68° – 500°F	0.0899	582	1660 – 1690

Minimum Casting Thickness vs. Heating Element and/or Cooling Tube Diameters

Casting Thickness	Maximum Available Element Diameter	Maximum Available Cooling Tube Diameter	Maximum Element and Cooling Tube Combination
	Heat Only	Cool Only	Heat and Cool
5/8" (15.9 mm)	0.26	1/4	—
3/4" (19.1 mm)	0.375	3/8	—
1" (25.4 mm)	0.43	1/2	—
1-1/4" (31.8 mm)	0.43	1/2	.260 and 3/8
1-3/8" (34.9 mm)	0.43	1/2	.315 and 1/2
1-1/2" (38.1 mm)	0.43	1/2	.430 and 1/2
1-5/8" (41.3 mm)	0.43	1/2	.430 and 1/2
1-3/4" (44.5 mm)	0.43	1/2	.430 and 1/2
Finned Casting
3/4" (19.1 mm)	0.375	—	—
7/8" (22.2 mm)	0.43	—	—
1" (25.4 mm)	0.43	—	—
1-3/4" (44.5 mm)	0.43	—	—

Linear Thermal Expansion Formula:
∆ L = Li × α × (Tf - Ti) × 10-6

∆ L = Change in Length Li = Initial Length

α = Coefficient of Linear Thermal Expansion

Tf = Final Temperature

Ti = Initial Temperature

Heating Element Electrical Specifications

Tubular Heater Diameter	.260"	.315"	.375"	.430"
Maximum Volts	240	277	480	600
Maximum Amps Per Element	15	30	40	40
Maximum Watt Density:
Aluminum Alloy	35 W/in2 on the element
*Bronze or Brass*	45 W/in2 on the element
Resistance Tolerance:	+10%, −5% Wattage Tolerance: +5%, −10%
Three Phase available depending on casting size.
Ground Studs can be added to most cast-ins.

Note: Tempco-Pak mineral insulated cable heaters can be used in place of tubular heating elements to fit physical constraints not possible with conventional heating elements. See catalog Section 5 for more details.

Cooling Tube Materials for Castings with Liquid Cooling

Tube Material	Tube OD and Wall Thickness
Stainless Steel (Standard)	1/4" O.D. × .028 wall
Stainless Steel (Standard)	3/8" O.D. × .035 wall
Stainless Steel (Standard)	1/2" O.D. × .049 wall
Stainless Steel (Optional)	5/8" O.D. × .049 wall
Incoloy® 840 (Optional)	1/2" O.D. × .049 wall
Tubing with heavier wall thickness is available upon request.

Casting Size & Weight Limitations

	Cylindrical	Platen
Minimum Inside Diameter:	1" (25.4 mm)	—
Maximum Inside Diameter:	48" (1219 mm)	—
Minimum Width:	—	1-1/2" (38.1 mm)
Maximum Width:	—	60" (1524 mm)
Minimum Length:	1-3/4" (44.5 mm)	4" (102 mm)
Maximum Length:	40" (1016 mm)	72" (1829 mm)
Finish:	125 RMS Standard or to customer spec.
Gap (two-piece cylindrical cast-in band heaters):	>1/4" (6.4 mm) top and bottom or to customer specification
Maximum Weight:
Aluminum	600 pounds
Bronze & Brass	300 pounds

NOTES: Cylindrical heaters are made with two half-round heaters. Cast-In thermal components can be made in any practical size, weight and geometric shape.