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Material Guide

Isostatic Graphite — Supplier & Machining Partner in India

TOYO TANSO authorised machining partner. IG-110, IG-430U, TTK-8, TTK-87 and ISO grades stocked and machined to your drawing. Full MTC and material traceability on every order.

Grade comparison →
Educational guide

What is Isostatic Graphite and Why Does it Matter?

Isostatic graphite is manufactured using cold isostatic pressing (CIP) — a process that applies equal pressure from all directions simultaneously. This produces a material with a uniform, fine-grain microstructure and near-isotropic properties, unlike extruded or moulded graphite where grain orientation varies by direction.

Uniform microstructure
CIP pressing eliminates grain orientation. Machined parts behave identically in any direction — critical for symmetrical components like heating elements and crucibles.
Ultra-fine grain size
Isostatic grades achieve grain sizes as small as 1–5 µm. Finer grain = smoother machined surfaces, sharper edges, and lower electrode wear in EDM applications.
High purity options
Purification to sub-5 ppm ash content is achievable in grades like IG-430U — required for semiconductor, solar, and nuclear applications where metallic contamination is fatal.
Superior mechanical strength
Isostatic pressing yields flexural strengths of 40–70 MPa vs 20–30 MPa for extruded grades. Components can be thinner and lighter without sacrificing reliability.

Isostatic Graphite Grades We Stock and Machine

We stock and machine all major TOYO TANSO isostatic grades plus ISO-series and EDM grades. Specification data from published TOYO TANSO datasheets — typical values.

GradeDensity (g/cm³)Flexural Str. (MPa)Grain Size (µm)Ash (ppm)Primary Use
TTK-8 1.80 49 20 <100 Vacuum furnace heating elements, fixtures, fasteners
TTK-87 1.82 55 10 <50 High-purity heating elements, compound semiconductor sintering
IG-110 1.77 38 20 <10 Nuclear-grade; CZ silicon crystal growth, high-purity sintering
IG-430U 1.82 55 10 <5 Semiconductor CVD/CVI, III-V compound crystal growth
IG-15 1.80 42 20 <100 General machined components, EDM electrodes
ISO-88 1.82 55 <20 <100 EDM electrodes, solar ingot growth, semiconductor
ISO-63 1.86 70 <10 <100 Sintering dies, high-load furnace structural parts
ETP-10 1.75 35 500 <100 Extruded rods, tubes, electrode blanks

Not sure which grade to specify? Send us your application parameters — we recommend the optimum grade for free.

How to Choose by Purity Requirement

Ash content (total metallic impurities in ppm) is often the single most important selection criterion. Here is the quick guide:

<100 ppm
TTK-8, IG-15, ISO-88, ISO-63
Vacuum heat treatment, EDM tooling, furnace fixtures
<50 ppm
TTK-87
High-purity sintering, compound semiconductor brazing
<10 ppm
IG-110
CZ crystal growth, high-temperature gas-cooled reactor (HTGR)
<5 ppm
IG-430U
Advanced semiconductor CVD, III-V crystal growth, ultra-clean sintering

Key Grade Details

TTK-8 Standard Isostatic — Vacuum Furnace Workhorse

The most widely used isostatic graphite grade for vacuum furnace components. TTK-8 offers balanced density (1.80 g/cm³), flexural strength (49 MPa) and electrical resistivity (13 µΩ·m). Suitable for heating elements, graphite trays, fixtures, and structural hot-zone components in vacuum and inert-atmosphere furnaces.

Key specs
Density1.80 g/cm³
Flexural str.49 MPa
Grain size20 µm
Ash<100 ppm
Resistivity13 µΩ·m
Applications
  • Vacuum furnace heating elements
  • Sintering trays and fixtures
  • Graphite fasteners (bolts, studs)
  • Continuous casting dies
  • Sealing rings and bushings
TTK-87 High-Purity — Semiconductor and Precision Sintering

Higher-purity variant of TTK-8 with ash content below 50 ppm. Chosen where metallic contamination from heating elements must be minimised — precision sintering of cutting tool inserts, compound semiconductor processing (GaAs, InP), and high-purity vacuum brazing. Mechanical properties identical to TTK-8.

Key specs
Density1.82 g/cm³
Flexural str.55 MPa
Grain size10 µm
Ash<50 ppm
Resistivity12 µΩ·m
Applications
  • High-purity vacuum furnace elements
  • Compound semiconductor sintering
  • Precision brazing fixtures
  • PVD coating chamber components
IG-110 Nuclear-Grade Ultra-High Purity

Nuclear-qualified isostatic graphite produced under the strictest purity controls. Ash content below 10 ppm with excellent radiation resistance. Qualified for high-temperature gas-cooled reactor cores. In commercial industry, used for Czochralski silicon crystal growth and float zone processing where extreme purity is required.

Key specs
Density1.77 g/cm³
Flexural str.38 MPa
Grain size20 µm
Ash<10 ppm
Resistivity11 µΩ·m
Applications
  • Czochralski silicon crystal growth
  • High-purity float zone processing
  • Research nuclear applications
  • Any process requiring <10 ppm ash
IG-430U Semiconductor Ultra-High Purity — <5 ppm Ash

The highest-purity TOYO TANSO grade we machine. Ultra-fine grain (10 µm), ultra-high purity (<5 ppm ash), used in the most demanding semiconductor fabrication environments. Required for advanced CVD/CVI reactors, III-V compound semiconductor growth (GaN, GaAs, InP), and precision CZ and FZ pulling systems.

Key specs
Density1.82 g/cm³
Flexural str.55 MPa
Grain size10 µm
Ash<5 ppm
Resistivity11 µΩ·m
Applications
  • Advanced semiconductor CVD/CVI reactors
  • III-V compound crystal growth
  • Precision CZ and FZ pulling
  • Any process requiring <5 ppm ash

Stock Forms Available

We machine from stock billets of all grades above. Standard billet dimensions available for immediate cutting:

Blocks / Slabs
Up to 600 × 600 × 300 mm. CIP-pressed, fine-grain. Available in TTK-8, TTK-87, IG-110, IG-430U, ISO-88, ISO-63.
Round billets / Cylinders
Diameter 50–500 mm, length up to 1200 mm. Suitable for rings, crucibles, bearings, and rotational parts.
Rods (extruded)
ETP-10 grade: diameter 10–300 mm, length up to 2000 mm. Fast delivery for electrode blanks and shaft applications.
Plates
Thickness 5–150 mm, width up to 500 mm. Flat plates for heating element segments, shelves, and boat components.

Industries That Use Isostatic Graphite

Vacuum heat treatment furnaces Semiconductor fabrication Solar PV ingot pulling Nuclear energy research EDM tool manufacture Sintering and hot pressing Glass fibre manufacturing Continuous casting (metals) Fuel cell manufacturing SiC crystal growth

Why Buy Isostatic Graphite from Expo Advanced Materials?

✓
TOYO TANSO authorised partner
We machine genuine TOYO TANSO material (TTK-8, TTK-87, IG-110, IG-430U) with full raw-material certificate and MTC on every shipment.
✓
Full material traceability
Every billet is traceable back to TOYO TANSO batch and mill certificate. Grade verification on request.
✓
ISO 9001:2015 certified
All machined parts inspected on CMM. Dimensional report and material certificate shipped with every order.
✓
Cost advantage 30–45%
India-manufactured machined parts at 30–45% below European equivalent pricing. Export to 30+ countries.
✓
No minimum order quantity
Machine from 1 piece prototype to 500+ piece production. Same quality, same documentation.
✓
Fast lead time
Standard orders 10–15 working days. Urgent jobs in 5–7 days for stocked billet grades. Air freight available.

How to Order Isostatic Graphite from India

1
Send your requirement
Share your grade, form (block/rod/plate), dimensions, and quantity. Or send a STEP/DXF drawing for machined parts.
2
We confirm and quote
Engineers confirm grade availability, verify billet stock, and return firm price and lead time within 24 hours.
3
We machine and ship
CNC machined, CMM inspected, shipped with material certificate and dimensional report. Door-to-door worldwide.
Related guides
→ TOYO TANSO Grade Comparison Table → Vacuum Furnace Graphite Components → EDM Graphite Electrodes

Ready to buy isostatic graphite from India?

Send your grade and dimensions — our engineers quote within 24 hours with full MTC.