Watlow Cable Heater Specifications

Coil/Cable Heaters

Low Mass with
High Versatility

The versatile Watlow® coil/cable heater can be formed into
a variety of shapes. Small diameter, high performing cable
heaters are fully annealed and readily bent to a multitude of
configurations.

The heater can be formed into a compact, coiled nozzle
heater supplying a full 360 degrees of heat with optional
distributed wattage. A straight cable heater can snake
through an equipment application. Flat, spiral configurations
can be used in high-tech manufacturing while a star wound
cable can be used for air and gas heating.

Different applications require different construction
methods, including one, two or four resistance wires;
parallel coil or straight wire; drawn or swaged sheaths; with
or without internal thermocouples; leads exiting from one
or both ends, and round, rectangular or square cable cross
sectionals.

Whatever the application requirement, a Watlow coil/cable
heater can be shaped to fit.

Performance Capabilities

• Continuous operating temperatures up to 1200°F (650°C)

with intermittent operating periods achieving up to 1500°F
(815°C) dependent on the type of element wire used

• Sheath watt densities on the cable to 30 W/in2

(4.65 W/cm2), and as high as 75 W/in2 (11.62 W/cm2)
subject to factory approval

• Maximum voltage up to 240V

Features and Benefits

High ductility

• Allows the heater to be cold-formed into almost

any shape

Low mass

• Allows quick response in both heating and cooling

Constructed with no open seams

• Enables operation in unusual environments, including

cryogenic and sub-freezing temperatures, high vacuum,
gaseous and liquid immersion heaters

• Decreases opportunity for corrosion

Straight Resistance Wire

OR

Welded
End Cap

Compacted MgO by
Swaging or Drawing

Sheath

With or Without a No-Heat Tail Section

Swaged Adapter

Crimp Ring

Parallel Coiled
Resistance Wire

Optional SS Hose
Lead Protection

Lead Wires

Constructed of standard 304 stainless steel, optional
316 stainless steel or alloy 600

• Provides high-temperature corrosion and oxidation

resistance along with ideal expansion properties

Heater sheath can be brazed

• Allows the permanent attachment of mounted fittings to

the heater, contact a Watlow representative for further
information

Sizes range from 0.040 in. (1.02 mm) to 0.188 in.
(4.8 mm) diameter

• Delivers a high volume of heat into a tiny space

Internal construction options

• Allows internal thermocouples and no-heat sections (not

available in all sizes)

©2013 Watlow Electric Manufacturing Company, all rights reserved.

®

STL-CAB-0813

Typical Applications

• Plastic injection molding nozzles

• Semiconductor manufacturing and wafer processing

• Hot metal forming dies and punches

• Sealing and cutting bars

• Medical, analytical and scientific instruments

• Restaurant and food processing equipment

Electrical Data and Coiling Limits

Sheath Surface Area Per Min. Bend Min. Coiled
Diameter Max. Linear Foot Radius Inside Diameter
in. (mm) Voltage in. (cm) in. (mm) in. (mm)

0.040 ± 0.002 (1.016 ± 0.051) 48 1.51 (9.740) 1/16 (1.6) 1/8 (3.2)

0.062 ± 0.002 (1.575 ± 0.051) 120 2.34 (15.098) 1/8 (3.2) 1/4 (6.0)

0.094 + 0.002 - 0.003 (2.388 + 0.051 - 0.076) 240 3.54 (22.840) 3/16 (4.8) 3/8 (9.5)

0.102 square ± 0.003 (2.591 ± 0.076) 240 4.90 (31.615) 1/4 (6.0) 1/2 (13.0)

0.102 ± 0.003 x (2.591 ± 0.076) x

0.156 ± 0.005 rectangular (3.962 ± 0.127) 240 6.19 (39.938) 1/4 (6.0) 1/2 (13.0)

0.125 ± 0.003 (3.175 ± 0.076) 240 4.71 (30.389) 1/4 (6.0) 1/2 (13.0)

0.157 ± 0.004 (3.988 ± 0.102) 240 5.92 (38.196) 5/16 (7.9) 5/8 (15.9)

0.188 + 0.003 - 0.006 (4.775 + 0.076 - 0.152) 240 7.09 (45.745) 3/8 (9.5) 3/4 (19.0)

0.128 square ± 0.003 (3.251 ± 0.076) 240 6.31 (40.712) 1/4 (6.0) 1/2 (13.0)

In most cases 30 W/in2 (4.65 W/cm2) is the safe allowable limit for cable watt density. Please contact your Watlow representative prior to
ordering >30 W/in2 cables.

Resistance/Wattage Tolerance ±10%.

Cable heaters can run on both ac and dc. Contact your Watlow representative for amperage limitations.

• Cast-in heaters

• Laminating and printing presses

• Air heating

• Textile manufacturing

• Heating in a vacuum environment

Coiling Tolerances

Coiled Width Tolerances Coiled I.D. Tolerances

Cable

Diameters

All Diameters Below 6 (152) + 0 - 1/8 (+0.00 - 3.18) Below 0.625 (Below 15.88) +0.000 - 0.015 (+0 - 0.38)
6 to 10 (152 to 254)
Over 10 (Over 254)

2.000 to 2.999 (51 to 76.18) +0.000 - 0.125 (+0 - 3.18)

3.000 to 3.999 (76 to 101.58) +0.000 - 0.250 (+0 - 6.35)

4.000 to 4.999 (102 to 126.98) +0.000 - 0.375 (+0 - 9.53)

5.000 and Over (127 and Over) +0.000 - 0.500 (+0 - 13.00)

When the O.D. of the coil is required as the critical dimension, it must be specified at the time of ordering so that proper coiling procedures can
be determined. I.D. and O.D. dimensions cannot be held on the same unit. Please contact your Watlow representative prior to ordering coiled
cable heaters requiring other than standard tolerances.

in. (mm) in. (mm) in. (mm) in. (mm)

Cable Straight Length Tolerances

Coiled Width Tolerances Coil I.D. Range Tolerances

+ 1/8 - 3/8

(+3.18 - 9.53) 0.625 to 0.999 (15.88 to 25.38) +0.000 - 0.030 (+0 - 0.76)

+ 1/4 - 1/4

(+6.35 - 6.35) 1.000 to 1.999 (25 to 50.78) +0.000 - 0.062 (+0 - 1.58)

Length

Tolerance

≤ 24 in. >24 in. ≤ 60 in. >60 in. ≤ 100 in. >100 in.
±3/8

in. ±1/2

Watlow® is a registered trademark of Watlow Electric Manufacturing Company.

in. ±1 in. ±1%

To be automatically connected to the nearest North American Technical Sales Office:

1-800-WATLOW2 • www.watlow.com • [e-mail]

International Technical Sales Offices: Australia, [phone] • China, [phone] • France, [phone]

Germany, +49 (0) 72 53 / 94 00-0 • India, [phone] • Italy, [phone] • Japan, [phone] • Korea, [phone]

Malaysia, [phone] • Mexico, [phone] • Singapore, [phone] • Spain, [phone]

Taiwan, [phone] • United Kingdom, [phone]