Hi-Speed Furnaces
for Heat Treating, Assaying and Dental Lab Applications
Download Product Manuals
Johnson Gas 120 Dental Furnace Pedestal Model No Safety Indicator
Johnson Gas 120 Manual No Safety
Johnson Gas 120 Pilot Safety
Johnson Gas 120 Ultra Violet Safety Control
Johnson Gas 120 Ultra Violet Safety Fuji Temp. Control
Standard Wiring Diagram/UV/Flame Rod Safety And Or Automatic Temp. Controls
Johnson Gas 120-121 Ultra Violet Safety and Honeywell Temperature
Johnson Gas 120-121 Ultra Violet Safety and Honeywell Temperature
120 Lining
Johnson Gas 121 Pilot Safety
Johnson Gas 125 Double Length Ultra Violet Safety Fuji Control
Johnson Gas 125 Ultra Violet Safety An Fuji Automatic Temperature Control
Wiring
125 Lining
Johnson Gas 142 Bench with Ultra Violet Safety and Guardsman
Johnson Gas 142 Pilot Safety
Johnson Gas 142 Pilot Safety Guardsman J Temperature Control
Johnson Gas 142 Pilot Safety Guardsman Temperature Control
Johnson Gas 142 Ultra Violet Safety Fuji Temperature Control
Johnson Gas 142 Ultra Violet Safety Manual Temperature Contr
142 Lining
142 Lining Drawing
142 Double Length Lining
142 Pilot Safety Lining
Johnson Gas 143 Manual Temperature Control No Safety
Johnson Gas 147 Ultra Violet Safety Control
Johnson Gas 654 Manual Temperature Control No Safety
Johnson Gas 654 Thermocouple Safety Control
Johnson Gas 70 Manual Temperature Control No Safety
Burner Port Lining
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OTHER FEATURES: Furnace door (Nos. 125 & 142) opens upward with ratchet arrangement allowing parts to be inserted or withdrawn without fully opening the door.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. |