THT · Through hardening and tempering
The whole section is heated above its transformation range, quenched in oil and tempered back to the hardness on the drawing. Strength through the part, not just at the surface.
- Furnace
- SQF-1, 2, 3 → TFC
Source · STEP process records; hardening temperature set to grade
What it does
Strength through the whole section.
For medium-carbon and alloy steels that need uniform strength and toughness: shafts, studs, fasteners and structural parts that carry load through the section.
- Specify it on through-hardening grades such as S45C.
- Tell us the hardness band (HRC or BHN) and where on the part it is measured.
- Temper temperature is chosen from the hardness band: lower for higher hardness, higher for toughness.
Typical cycle
The cycle, as we run it.
THT
Through hardening · tempering
- Pre-heat400 ± 10 °C
- Hardenset to grade
- Quenchoil 50–100 °C
- Temperto hardness · 60 ± 5 min
Pre-heat, quench oil and temper soak from STEP records. Hardening temperature depends on grade; actual cycle per part specification.
Route through the plantSpecifications we control
Hardness through the section, and how it is set.
Tighter bands are quoted per part.
- Hardness
- Final hardness in HRC, set by the temper.
- Rockwell · per sampling plan
- Hardening temperature
- Set to the grade.
- Digital controller · logged
- Quench
- Oil, 50–100 °C. As-quench hardness checked before the temper.
- Oil temperature logged per charge
- Temper
- Set to the hardness band; 60 ± 5 min soak, recorded.
- TFC · check TM01, TM03
Typical work
Grades and parts we through harden.
Material grades
- S45C
Other grades on request.
Part types
- Shafts
- Studs
- Pins
- Valves and seats
- Plates
Next step