Graphite Hot Zone Cylinders
Large-diameter isostatic graphite cylinders forming the inner hot zone shell of vacuum and atmosphere furnaces. High purity, low outgassing, precision-bored to close tolerances. Single-piece and segmented designs available.
Graphite Hot Zone Cylinders are the primary structural element of a vacuum furnace hot zone. The cylinder surrounds the heating elements and serves as the inner thermal barrier, retaining heat within the working zone while protecting the furnace shell from radiant energy.
Manufactured from fine-grained isostatic graphite — typically TOYO TANSO IG-11, IG-15, or equivalent high-purity grades — the cylinders are bored and turned to close diametrical tolerances so that thermal shields, heating elements, and support rings fit precisely without binding or excessive clearance. High purity grades (<5 ppm total ash) are specified for semiconductor, solar, and medical device applications where contamination budgets are tight.
Single-piece cylinders up to 1200 mm diameter are achievable from large isostatic billets; for larger furnaces, precision-machined segmented ring assemblies with interlocking joints maintain concentricity and seal the working zone. All machined surfaces can be finished to Ra 1.6 µm or better on request.
Replacement hot zone cylinders are supplied to match OEM drawings or reverse-engineered from your worn component. Lead times are typically 3–6 weeks depending on diameter and length.
