NMX‑PNF‑01 / Rev 01 / Bell Furnace · AMS 2750E / Noida · India 2026 · Product Page

NMX-PNF-01 · ENGINEERED TO ORDER — HOT-WALL BELL FURNACE

Plasma nitriding furnace. A harder skin, grown not coated.

Name: Plasma Nitriding Furnace — Hot-Wall Bell Type
Brand: Neometrix

Nitriding hardens a steel part from the surface in, by diffusing nitrogen into it — no coating to chip, almost no distortion. This furnace does it the clean way: a glow discharge under vacuum. A hot-wall SS304L bell chamber takes a 500 kg charge, holds 350–560 °C to ±5 °C (AMS 2750E), and an IGBT plasma generator makes the parts themselves the cathode. Engineered to order in Noida.

Enquire — nitriding furnace Capability sheet (PDF)

Representative render — a hot-wall vertical bell plasma nitriding furnace in a clean industrial heat-treatment shop: a tall cylindrical SS304L bell on a base-plate hearth, with a control panel, gas cylinder rack and vacuum unit alongside

Fig · 01 The furnace — representative render of the bell station and controls

Process Temp

350–560°C · ±5 °C AMS 2750E

Charge

500kg · Ø950 × 1200 mm bell

Plasma

40kVA · IGBT · 0–600 V

Uniformity

±5°C · AMS 2750E survey

Ultimate Vacuum

5×10⁻²mbar · rotary + roots

ISO 9001 / 14001 Pyrometry to AMS 2750E Make in India · Class 1 PLC + web SCADA Noida · India

Overview

Hardness where it wears, toughness underneath.

A gear tooth, a die face, a hydraulic rod fails at its surface — wear, scuffing, fatigue, corrosion. Nitriding answers that by diffusing nitrogen into the surface to form a hard, tough case, while the core keeps its original toughness. Because it happens low and slow, under 560 °C, the part barely moves — no quench, minimal distortion, no coating that can flake. The plasma route does it cleanest of all.

Representative render — the raised bell chamber of the furnace with steel components stacked on the SS304L base-plate hearth, bathed in the soft violet glow of a nitrogen-hydrogen plasma discharge

Fig · 02 The glow — components on the hearth in a plasma discharge (representative render)

In plasma (ion) nitriding the charge itself is made the cathode. The chamber is pumped down, back-filled with a low-pressure nitrogen-and-hydrogen atmosphere, and a pulsed DC voltage struck between the wall and the parts lights a glow discharge. Ions bombard the surface, sputter it clean, heat it, and drive nitrogen into the steel to grow the nitride case — all controlled by gas chemistry, pressure, temperature and the pulse itself, not by a furnace atmosphere you cannot steer.

This is a hot-wall bell furnace: the parts sit on a water-cooled SS304L base plate, the SS304L bell lowers over them, and external serpentine tubular heaters bring the whole working volume to temperature and hold it to ±5 °C across the load — surveyed to AMS 2750E, the aerospace pyrometry standard. A PLC and web-enabled SCADA run the recipe, log every parameter and print the report, so one recipe repeats across the batch, part after part.

The case is grown into the steel, not laid on top of it. Nothing to chip, nothing to peel — and the part comes out almost the same size it went in.

Process · Plasma Under Vacuum

Steered, not just heated

Gas chemistry, pressure, temperature and the pulsed discharge are each controlled, so the case depth and the compound (white) layer are tuned to the part — argon and hydrogen for stainless steels, nitrogen and hydrogen for carbon and alloy steels, with a sputter-clean step first.

Uniformity · AMS 2750E

±5 °C across the load

Hot-wall heating plus a dedicated temperature-uniformity survey fixture hold and prove ±5 °C across the working volume to AMS 2750E — the pyrometry discipline aerospace and defence heat-treaters are audited against, so results are repeatable and traceable.

Control · Recipe to Report

One cycle, repeated exactly

A PLC with web-enabled SCADA stores recipes, drives the whole cycle automatically, logs temperature, vacuum, gas flow and plasma parameters, and generates the batch report — with safety interlocks on over-temperature, the door, the vacuum and the gas train.

Architecture

Chamber, vacuum, gas and the glow.

The section below is the furnace as a system — the bell chamber and its heating, the vacuum train underneath, the metered gas panel, the IGBT plasma generator that lights the discharge, and the control that runs it.

FIG · 03HOT-WALL BELL FURNACE · SECTIONAL ELEVATION

Fig · 03 SS304L bell + serpentine heaters → charge as cathode on the base plate · rotary+roots vacuum, MFC gas panel and IGBT plasma generator around it

Arc · 01

Bell Chamber & Heating

A single-wall SS304L bell (≈Ø950 × 1200 mm, 500 kg charge) with external serpentine tubular heaters and thick ceramic-blanket insulation that keeps the skin under 50 °C. Wall to 650 °C, process 350–560 °C, held to ±5 °C under thyristor control. The water-cooled SS304L base plate carries the charge and seals to the bell through twin Viton O-rings with an inter-seal support vacuum that blocks air ingress; two quartz view ports watch the glow. A motorised lift raises the bell to load.

Arc · 02

Vacuum Train

A rotary pump (~250 lpm) backed by a roots pump (~500 lpm) evacuates the chamber to a working vacuum of 5×10⁻¹ and an ultimate of 5×10⁻² mbar, housed in the base stand. Vacuum is read by an indigenous pirani gauge and an absolute (capacitance) transmitter, each behind a protection valve, and interlocked through the control panel — so the process only runs inside its pressure window.

Arc · 03

Gas & Plasma

A gas panel meters hydrogen, nitrogen and argon through mass-flow controllers (≤500 sccm), isolation and needle valves and mixing manifolds — programmed ratios for flush, sputter-clean and nitride cycles. The IGBT pulsed plasma generator — unipolar/bipolar, 0–600 V, up to 10 kHz, 40 kVA, pulse 10–1990 µs — strikes and holds the glow, with arc suppression under 1 µs so an arc cannot mark a part.

Arc · 04

Control & Utilities

Two panels — plasma and full-system — run on a PLC with web-enabled SCADA: recipe storage, automatic cycle control, data logging and report generation on a ≥19-inch display, with UPS-backed instrumentation. Around them: an AMS 2750E temperature-uniformity survey fixture, tangential cooling blowers for fast post-process cool-down, a closed-loop water chiller, DM-water utilities and an electric/hydraulic job-loading stacker.

Holding a nitriding, heat-treatment or surface-engineering requirement? Send the specification — clause-by-clause compliance matrix within two working days · [email protected]

Send tender spec

Specifications

Reference specification, built to your charge.

The furnace is engineered to order — chamber size, charge, gas chemistry, plasma rating and automation are configured to the customer’s parts and throughput. The parameters below describe the reference bell station.

Full specification — expand

Type	Hot-wall vertical bell plasma (ion) nitriding furnace — glow-discharge nitriding under vacuum · design, manufacture, installation, commissioning & proving
Application	Surface hardening of steel components — tool steels, alloy steels, stainless steels (gears, dies & moulds, shafts & rods, cutting tools, wear parts)
Vacuum Chamber	Vertical bell, single-wall SS304L · working volume ≈Ø950 × 1200 mm · single-station 500 kg charge · serpentine tubular heaters · ceramic-blanket insulation, skin <50 °C · 2× Viton O-rings with inter-seal support vacuum · 2× 100 mm water-cooled quartz view ports · SS304L water-cooled base plate
Temperature	Wall max 650 °C · process 350–560 °C · uniformity ±5 °C to AMS 2750E · thyristor control with programmable PID + independent over-temperature controller · K/N-type MI-sheathed thermocouples, ±2 °C, traceable to national standards
Vacuum System	Rotary pump ≈250 lpm + roots pump ≈500 lpm · working 5×10⁻¹, ultimate 5×10⁻² mbar · pirani + absolute (capacitance) gauges, protection-valved · SS pipework, bellows, quick clamps
Plasma Generator	IGBT pulsed — unipolar/bipolar · 0–600 V programmable · up to 10 kHz · 40 kVA · pulse 10–1990 µs, PLC-controlled · arc switch-off <1 µs · water-cooled view port for the glow
Gas Feeding	Mass-flow controllers (≤500 sccm), isolation / needle / solenoid valves, mixing manifolds, PRVs · 3 gases — H₂, N₂, Ar — plus a separate N₂ flush line · Ar+H₂ for stainless, N₂+H₂ for carbon/alloy steels · double-stage regulators · flows/pressures sensed & interlocked
Control & SCADA	Two panels (plasma + system) · automatic PLC via internal PC, keyboard / mouse / touchscreen · web-enabled SCADA — recipe storage, data logging, report generation · ≥19″ display, A4 laser printer, 30-min UPS · per-phase ammeter/voltmeter · 6 thermocouples (control + over-temp + 4 load)
Cooling	Tangential centrifugal blowers for fast post-process bell cooling · closed-loop water chiller for seals & view ports
Utilities	DM-water loop ≈200 LPM @ 1.5–2 kg/cm², 22–35 °C, ≈60 TR tower · 2000 L overhead emergency tank · N₂/Ar 99.999% @ ≈60 m³/h · PVC exhaust with oil trap · electric/hydraulic job-loading stacker
Temperature-Uniformity Survey	Dedicated AMS 2750E TUS fixture with K-type thermocouples & recorder for periodic pyrometry checks
Safety	Safety mechanisms on chamber, pumps, heating, plasma, gas train & control · door interlock · over-temperature protection · audio-visual interlock alarms (over-temp, single-phasing, element failure)
Documentation & Support	Operation, layout, electrical & maintenance manuals, PM checklists, PLC program, calibration certificates · foundation kit (vibro-mounts) · operator & maintenance training · essential-spares kit · remote diagnostics · 24-month warranty
Status	Engineered to order — chamber size, charge, gas chemistry, plasma rating and automation configurable to the customer’s parts and throughput

PDF · 1 page

Plasma Nitriding Furnace — Capability Sheet

Tender Response

Send your specification — compliance matrix in two working days

Configurations

One process, many charges.

Requirements call it a plasma nitriding furnace, an ion nitriding furnace, a glow-discharge nitriding system or a bell-type surface-hardening furnace. The architecture answers all of them, sized to the parts in front of it.

Cfg · 01

The Reference Bell

The Ø950 × 1200 mm, 500 kg bell station on this page — SS304L chamber, rotary+roots vacuum, IGBT plasma, PLC/SCADA — engineered to order, then installed and proved to AMS 2750E on site.

Cfg · 02

Charge Size

Chamber diameter, height, charge mass and heater rating scaled from small tool-room loads to large production charges — the bell architecture and controls stay the same, the working volume grows to the parts.

Cfg · 03

Process & Gas Chemistry

Gas set and recipes tailored to the metallurgy — nitriding or nitro-carburising, compound-layer control, and chemistries for tool, alloy and stainless steels — with the pulse and pressure windows configured to the target case.

Cfg · 04

The Wider Process Line

Vacuum, gas-handling and PLC/SCADA-controlled process systems from the same engineering line — built to the same instrumentation, interlock and documentation discipline.

Applications

Where it serves.

Wherever a steel part has to survive its own surface.

A · 01Tool rooms & die shops — dies, moulds, punches and cutting tools

A · 02Automotive & driveline — gears, crankshafts, cam & cylinder components

A · 03Hydraulics & fluid power — piston rods, spools, valve parts against wear

A · 04Defence & ordnance components — wear- and fatigue-critical steel parts

A · 05Bearings, pumps & textile / plastics machinery — anti-galling surfaces

A · 06Stainless & specialty steels — surface hardening without compromising corrosion resistance (low-temperature route)

FAQ

Common questions.

Plain-language answers from the engineering team.

Q · 01 What is plasma nitriding, and how is it different from gas nitriding or coating?

All nitriding diffuses nitrogen into a steel surface to grow a hard case — it is not a coating laid on top, so there is nothing to chip or peel, and because it runs below 560 °C with no quench, the part barely distorts. Plasma (or ion) nitriding does it in a vacuum using a glow discharge instead of a hot ammonia atmosphere: the parts are made the cathode, ionised gas bombards and cleans the surface, and the process is steered by gas chemistry, pressure and the electrical pulse. That control means a thinner, better-defined case, tunable compound (white) layer, far less gas consumption, and — unlike gas nitriding — it readily nitrides stainless steels by sputtering through their passive oxide first.

Q · 02 Why a hot-wall bell design?

In a hot-wall furnace the heat comes from serpentine heaters on the chamber wall, surrounding the load, rather than from a single internal element — that is what makes it straightforward to hold ±5 °C across a 500 kg charge and survey it to AMS 2750E. The bell form loads from the top: the charge is stacked on a fixed base-plate hearth and the bell is lowered over it, which suits tall or awkward parts, gives clean access for loading, and seals through twin O-rings with a support vacuum between them so no air leaks into the process. Heating the wall, not the parts, also keeps the plasma free to do the surface chemistry rather than the bulk heating.

Q · 03 What materials can it treat, and what does nitriding actually improve?

Tool steels, alloy steels and stainless steels — gears, dies and moulds, shafts and rods, cutting tools and wear parts. Nitriding raises surface hardness and, with it, resistance to wear, scuffing and galling; it improves fatigue strength by putting the surface into compression; and it adds corrosion resistance. The gas chemistry is chosen for the metal — argon and hydrogen to sputter through the passive layer on stainless, nitrogen and hydrogen for carbon and alloy steels — and the recipe sets how deep the case grows and whether a compound layer is formed or suppressed, which is what a given part actually needs.

Q · 04 Why does AMS 2750E and ±5 °C uniformity matter?

Case depth and hardness depend on temperature, so if one corner of the load runs hotter than another, the parts come out different. AMS 2750E is the aerospace pyrometry standard that governs how furnace temperature is controlled, calibrated and surveyed; holding the working volume to ±5 °C and proving it with a temperature-uniformity survey is what lets a heat-treater guarantee every part in the charge got the same cycle. It is the difference between a process that is repeatable and auditable and one that merely looks right — which is why aerospace, defence and quality-critical shops specify it.

Q · 05 How is the cycle controlled and made repeatable?

Everything runs from a PLC with web-enabled SCADA. An operator selects a stored recipe; the system pumps down, runs the sputter-clean and nitride steps, meters the gases through mass-flow controllers, drives the pulsed plasma and the wall heaters, and logs temperature, vacuum, gas flow and plasma parameters throughout — then generates the batch report. Safety interlocks watch over-temperature, the door, the vacuum and the gas train, with audio-visual alarms. Because the recipe and the data are stored, the same recipe repeats part after part, and any deviation is on the record.

Q · 06 What is the current status — and can you build to our specification?

The furnace is engineered to order. The reference bell station on this page — SS304L chamber, rotary+roots vacuum, IGBT plasma and PLC/SCADA — is designed to the AMS 2750E regime and is sized and configured per order to the customer’s charge, parts and throughput, then installed, commissioned and proved on site with operator training. Send your parts, load size and target case and the engineering team returns a clause-by-clause compliance matrix within two working days. Export engagements are managed end-to-end, subject to Government of India authorisation.

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Process & automation systems from Neometrix.

Engineered and manufactured at our Noida facility to industrial and QA standards.

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Get a quotation

Send your nitriding
furnace specification.

The Projects desk replies within two working days with a line-by-line compliance matrix and a budgetary quotation. Write to [email protected] or use the form.

Enquire — surface engineering Capability sheet (PDF) +91 7777 876 876

ISO 9001 / 14001 PYROMETRY TO AMS 2750E MAKE IN INDIA · CLASS 1 MADE IN NOIDA · INDIA

Plasma nitriding furnace. A harder skin, grown not coated.

Hardness where it wears, toughness underneath.

Steered, not just heated

±5 °C across the load

One cycle, repeated exactly

Chamber, vacuum, gas and the glow.

Bell Chamber & Heating

Vacuum Train

Gas & Plasma

Control & Utilities

Reference specification, built to your charge.

One process, many charges.

The Reference Bell

Charge Size

Process & Gas Chemistry

The Wider Process Line

Where it serves.

Common questions.

Process & automation systems from Neometrix.

Drive & Control Automation System

Gas Distribution System

LP Shaft Torsion Fatigue Testing Machine

Send your nitriding
furnace specification.

Similar Products

Share This Page

Plasma nitriding furnace. A harder skin, grown not coated.

Hardness where it wears, toughness underneath.

Steered, not just heated

±5 °C across the load

One cycle, repeated exactly

Chamber, vacuum, gas and the glow.

Bell Chamber & Heating

Vacuum Train

Gas & Plasma

Control & Utilities

Reference specification, built to your charge.

One process, many charges.

The Reference Bell

Charge Size

Process & Gas Chemistry

The Wider Process Line

Where it serves.

Common questions.

Process & automation systems from Neometrix.

Drive & Control Automation System

Gas Distribution System

LP Shaft Torsion Fatigue Testing Machine

Send your nitridingfurnace specification.

Similar Products

Share This Page

Send your nitriding
furnace specification.