Routes register

The register holds 25 working routes across seven processes. The bands are given for a typical section; for a specific part we refine temperature and soak against the drawing.

The picker below reads the same register that is published in machine-readable form on the documents page. Choose a grade and, if needed, a target hardness, and the list narrows itself. With scripting off the full table works on its own, and it is the source of truth.

Steel grade Process Hardness, HRC

Process	Grade	Heat, °C	Quenchant	Hardness	Note

Full register

Quench hardness is given as-quenched; after tempering it drops by the amount shown in the tempering section. For carburised grades the result column is the case hardness, while the core stays within 30–42 HRC.

Full routes register - 25 entries
Process	Grade	Heat, °C	Quenchant	Result	Note
Quenching	45	820–840	polymer–water	45–50 HRC	Prone to distortion, straightened after tempering.
Quenching	40Kh	840–860	oil I-20A	48–52 HRC	The bulk of what the shop runs.
Quenching	40KhN	820–840	oil I-20A	48–53 HRC	Hardens through up to 60 mm of section.
Quenching	65G	810–830	oil I-20A	55–60 HRC	A medium temper follows, for springiness.
Quenching	U8	780–800	water	58–62 HRC	Thin sections go into polymer, never water.
Quenching	9KhS	840–860	oil I-20A	60–63 HRC	Tooling grade with a two-stage preheat.
Quenching	ShKh15	830–850	oil I-20A	61–65 HRC	Soak is a minute and a half per millimetre of section.
Quenching	Kh12MF	1020–1040	oil or air	58–62 HRC	Preheat at 850 °C, then austenitising.
Tempering	low	150–250	still air	−1…−3 HRC	Relieves stress while keeping the as-quenched hardness.
Tempering	medium	350–450	still air	42–48 HRC	Springiness for springs and retainers.
Tempering	high	550–650	oil or air	28–34 HRC	Toughening that leaves a tough core.
Carburising	20	920–940	oil I-20A	58–62 HRC	Hard case over a tough core.
Carburising	20Kh	920–940	oil I-20A	58–62 HRC	Gears and splines working under wear.
Carburising	18KhGT	920–940	oil I-20A	58–62 HRC	Gear wheels with a fine grain.
Carburising	12KhN3A	920–940	oil I-20A	58–62 HRC	Impact loads with a tough core.
Carburising	20KhGNM	920–940	oil I-20A	58–62 HRC	Loaded transmissions.
Normalising	45	850–870	still air	170–210 HB	Evens out structure after forging.
Normalising	40Kh	860–880	still air	190–230 HB	Done before machining.
Normalising	65G	810–840	still air	200–240 HB	Prepares rolled stock for cutting.
Normalising	20Kh	880–900	still air	130–180 HB	Before carburising where needed.
Full annealing	40Kh	840–860	with the furnace to 500 °C	180–220 HB	Lowers hardness for cutting.
Full annealing	U8	740–760	with the furnace to 500 °C	170–207 HB	Softens tool steel.
Spheroidise annealing	ShKh15	780–800	with the furnace, 20 °C/h	179–207 HB	Prepares bearing steel for quenching.
Spheroidise annealing	9KhS	770–790	with the furnace, 20 °C/h	197–229 HB	Granular pearlite for machining.
Stress relief	any structural	600–650	with the furnace to 500 °C	unchanged	After welding and rough machining the hardness does not change.

The heating soak is taken from the section: a minute and a half for every millimetre. If a grade is missing, write to order@ironquench.cloud and we will pick one from the handbook and agree the temperature by email.