Hi-Speed Furnaces

for Heat Treating, Assaying and Dental Lab Applications

Johnson’s rugged, low cost heat treating furnaces have been in wide use in industrial tool rooms, tool and die shops, assay labs, dental labs and school shops, for over 80 years. These powerful, highly efficient furnaces are designed to meet the demands of industrial heat treating for speed, accuracy, efficiency and durability.

NO. 142 AND NO. 125
HI-SPEED HEAT TREATING FURNACES
Rugged Construction, Fully Insulated

No. 142 (left) and No. 125 With Ultra Violet Safety System and Automatic Temperature Control (right)

 

 

RUGGED CONSTRUCTION: Massively built of heavy gauge steel with special fire box reinforcement and cast iron doors, front sections and burner ports.

FULLY INSULATED: Highest quality insulating fire brick insures efficient, low-cost operation and comfortable working conditions.

HIGH SPEED DESIGN: Blast type burners and Johnson’s powerful blowers insure fast heat up and even temperatures. (1500°F. in 15 minutes; 2300°F. in 50 minutes).

EASY, SAFE OPERATION: All Johnson Hi-Speed furnaces are equipped with Ultra Violet safety systems. They also feature push button spark ignition lighting and solid state air controllers that insure simple, accurate furnace adjustment and operation.

OTHER FEATURES: Furnace door (Nos. 125 & 142) opens upward with ratchet arrangement allowing parts to be inserted or withdrawn without fully opening the door. Special tool steel foil wrap is also available.

AUTOMATIC TEMPERATURE CONTROLS: Fully automatic temperature controls are recommended for Johnson Heat Treating Furnaces. Johnson Engineers have developed a highly accurate control system. This control system extends the furnace temperature range to 600°F.-2350°F. The equipment is housed in the furnace cabinet which is convenient for the operator, protects this equipment from shop hazards, and provides valuable sound proofing.

No. 142 Double Length with Ultra Violet Safety (left) and Number 120 Pedestal with Console and Ultra Violet Safety (right)

 

NO. 121 AND NO. 143 HEAT TREATING AND FORGE FURNACES (Not pictured)
Popular adaptation of the standard No. 120 and No. 142 Furnaces. Especially suitable for the shop where light forging is done as well as heat treating. Special hard refractory bottom and hearth rests are provided. The hearth plate is used for heat treating; plate is removed for forge work so the parts to be forged can be placed on hearth rests.

Time To Temperture Curve

 

Tool Steel Foil Wrap

 

NEW TOOL STEEL FOIL WRAP
For scale-free heat treating of air hardening steel. Eliminates Ni-chrome box packing. Parts heat fast, cool fast. No special controls or atmosphere furnace required. Simply place tool in wrap; fold; crimp edges; heat treat in usual way.
 

Specifications:

 

Furnace
Number

Firebox
Dimensions

(Inches)
Overall
Dimensions

(Inches)
Door
Opening

(Inches)
Hearth Size
Work Area

(Inches)
Gas
Connection

(Inches)
Gas
Input

 
Approx.
Shipping
Weight
  H W L L W H H W L W Pipe Size BTU/hr. Lbs.
125 12 13 16-1/2 35 27 73 12 11-1/4 16 9-1/2 3/4 180,000 675
125 Special Length 12 13 23-1/2 43 27 73 12 11-1/4 23 9-1/2 3/4 180,000 800
125 Double Length 12 13 33 53 27 73 12 11-1/4 32 9-1/2 1 400,000 990
 
142 7 13 16-1/2 26 27 58 7 11-1/4 16 9-1/2 3/4 180,000 580
142 Special Length 7 13 23-1/2 33-1/2 27 58 7 11-1/4 23 9-1/2 3/4 180,000 770
142 Double Length 7 13 33 43 27 58 7 11-1/4 32 9-1/2 1 400,000 895
 
143 6-1/4 13 16-1/2 26 27 58 6-1/4 11-1/4 16 9-1/2 3/4 180,000 600
143 Double Door 6-1/4 13 16-1/2 26 27 58 6-1/4 11-1/4 16 9-1/2 3/4 180,000 650
 
120 Bench 5 7-3/4 13-1/2 19-1/2 22 18 5 7-3/4 13-1/4 5 3/4 90,000 184
120 Pedestal 5 7-3/4 13-1/2 19-1/2 22 48 5 7-3/4 13-1/4 5 3/4 90,000 216
 
121 Pedestal 4-1/4 7-3/4 13-1/2 19-1/2 22 48 4-1/4 7-3/4 13-1/4 5 3/4 90,000 226
121 Double Door 4-1/4 7-3/4 13-1/2 19-1/2 22 48 4-1/4 7-3/4 13-1/4 5 3/4 90,000 300
Gas Pressure 4-1/2″ to 14″ W. C.   Nat. Gas; 11″ W. C.   LP Gas
Above furnaces (Except 142 & 125 Double Length) furnished with No. 1218 Blower.
142 and 125 Double Length include No. 1207 Blower.