Square Cartridge Heaters

For applications where a drilled hole is not practical, MPI Morheat offers square cartridge heaters. Unlike square cartridge heaters from other manufacturers, our square cartridge heaters are swaged, allowing them to be used in high temperature and high watt density applications.

Square heaters are ideal for milled slots in long platens where drilling a long hole would be too difficult. Square heaters are also much easier to remove from a slot after extended high temperature usage than round heaters are from a drilled hole.

Specifications
3/8 1/2 5/8
Maximum Cross Section 0.374 0.499 0.624
Minimum Cross Section 0.369 0.494 0.619
Standard Lead Wire 22 22 18
Maximum Amp. 9 9 15
Maximum Lead Wire 22 18 18
Maximum Amps With 9 15 15
Maximum Volts 300 300 300
Lead Wire Temp 550 °C 550 °C 550 °C
Applications
Typical applications for square cartridge heaters include, but are not limited to:
  • Bag Sealing
  • Long Platens
  • Cutting Jaws
Cold Section
Heater Length .375″ Square .500″ Square .625″ Square
Under 3″ Long .25 .30 .38
Over 3″ Long .90 .90 1.00
Leads
Wire type Maximum Recommended Temperature Comments
Duraflex 550°C Highest temperature rating, excellent, durable, user friendly. This is our standard lead wire.
MGT 450°C Good high temperature wire.
Ultralead 450°C Excellent, durable wire, good for high temperature applications.
Teflon 250°C Good for areas where a small diameter wire is needed.
Silicone Rubber 200°C Good moisture resistance
Braided Silicone Rubber 200°C Inexpensive wire, good for non-abrasive applications.
SJO Cord 90°C Rubber jacket, resistant to oil and moisture. For use on 3/8” diameter and larger.

Stainless Steel Braid

Stainless steel braid for square cartridge heater
  • Swaged in stainless steel braid provides excellent abrasion protection while allowing the leads to be bent in a tight radius.
  • Because the braid is swaged in, it is extremely resistant to pulling out of the heater.
Unheated Length at Lead End of Heater
Heater Length 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Under 3″ Long .25 .20 .35 .29 .39 .39 .54
Over 3″ Long .86 .79 .94 .84 1.01 1.00 1.20

Right Angle Braid

Square Heater with Right Angle Braid
  • Right angle stainless steel braid offers the same advantages as swaged in stainless steel braid, but allows use in tight spaces.
  • When ordering, please specify the overall length.
Unheated Length at Lead End of Heater
Heater Length 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Under 3″ Long .20 .20 .25 .29 .39 .39 .24
Over 3″ Long .81 .79 .84 .84 1.01 1.00 .31
Extension Length .31 .31 .37 .37 .44 .44 .75

Stainless Steel Flexible Conduit

Stainless steel flexible conduit for cartridge heater
  • Flexible conduit (also known as armor or hose) provides maximum lead protection from abrasion but cannot be bent quite as sharply as stainless steel braid.
  • Flexible conduit is swaged into the heater for maximum protection.
Unheated Length at Lead End of Heater
Heater Length 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Under 3″ Long .62 .60 .30 .23 .39 .39 .54
Over 3″ Long 1.23 1.20 .89 .84 1.01 1.00 1.2
Conduit O.D. .25 .303 1.4″ .303 .37 .48 .48

Right Angle Stainless Steel Conduit

Square Heater with Right Angle Conduit
  • Right angle stainless steel conduit offers the advantages as swaged in stainless steel conduit but allows use in tight spaces.
  • When ordering, please specify the overall length.
Unheated Length at Lead End of Heater
Heater Length 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Under 3″ Long .55 .60 .65 .70 .90 .80 .24
Over 3″ Long .81 .79 .84 .84 1.01 1.00 .31
Extension Length .31 .37 .37 .37 .44 .44 .75
Conduit O.D. .25 .25 .33 .37 .37 .37 .37

Sleeving

Type Max Rec. Comments
Silicone Rubber Fiberglass Sleeving 200°C Can sleeve both leads together or each lead separately.
Fiberglass Sleeving 240°C Good for lead protection and used over crimps.
Configurations

Standard Swaged-In Leads

square heater with standard construction
  • Available in .375″, .500″ and .625″ diameters

Right Angle Leads

square heater with right angle leads
  • Right angle leads are ideal for applications where space is limited.
  • Leads are covered with silicone impregnated fiberglass sleeve where they exit the heater.
  • When ordering, please specify the overall length.
Unheated Length at Lead End of Heater
Heater Length 1/4″ 5/16″ 3/8″ 1/2″ 5/8″ 3/4″ 1″
Under 3″ Long .20 .20 .25 .29 .39 .39 .24
Over 3″ Long .81 .79 .84 .84 1.01 1.00 .31
Extension Length .25 .25 .31 .37 .37 .37 .75
Other Options
Watt Density
Clearance (Inches) 1200°F 1000°F 800°F 600°F 400°F 200°F
0.002 105 200 225 225 225 225
0.003 90 150 220 225 225 225
0.004 75 130 160 225 225 225
0.005 65 105 150 210 225 225
0.007 50 75 110 150 175 225
0.010 45 65 80 110 150 170
0.015 35 55 70 80 105 120
0.030 30 45 60 65 75 80
0.060 20 30 35 40 45 50
0.100 15 25 30 35 35 35