Toll Firing / Testing Services

In conjunction with our laboratory, which focuses on bench-scale testing, Harrop offers a Toll Firing Service to fire larger quantities of  ceramics products or materials. Firing can be performed on quantities as small as a few of pounds or a pieces, and as large as several tons or thousands of pieces. Our toll firing service may be the ideal solution to your needs for interim production of existing products, or for firing sufficient quantities of new products for meaningful market samples. In these cases, you simply ship us your materials, we fire them per your instructions, and we ship the materials back to you. Or, in the case of your developing new compositions or products, Harrop also offers technical consulting services, in conjunction with toll firing, to help you determine the feasible firing cycles. Our testing laboratory is also available to provide custom process monitoring, and to conduct pre-firing and/or post-firing testing of your products at your request.

Firing Facility

Harrop’s 8,000 sq. ft. facility for firing ceramics contains some 17 electric and gas-fired periodic kilns & ovens with temperature capabilities up to 1,700°C and atmosphere control. Sizes range from 1 cu. ft. to 27 cu. ft. electric kilns, and from 2 cu. ft. to 57 cu. ft. gas-fired kilns., Our facility also operates a 7” dia. x 14 ‘ long electric rotary kiln. Materials can be handled on pallets, or in crates, drums, bags or super sacks. In handling powders and granular materials, three independent, sealed process rooms are maintained to isolate materials, minimizing cross-contamination. Kiln furniture required for loading products into kilns can be furnished by either you or Harrop, at your choosing.  

Materials Evaluation Laboratory

The Materials Evaluation Laboratory has been an in-house testing facility for many decades, providing essential materials science expertise on the thermal behavior of  ceramics and other materials to Harrop engineers in designing industrial kilns and dryers. At the request of many clients, we re-organized this group in 1970 to include an independent, fee-based laboratory for thermal testing of ceramics, metals, polymers, and composites. Since then, we have serviced thousands of customers, for one-time analyses, for multi-sample R&D projects, and for on-going QC programs.


  • New Product Development
  • Firing Cycle Optimization
  • Product Quality Investigation
  • Prototype Production

Equipment Schedule

  • Electric Kilns – Box and elevator, up to 27 cu. ft. setting. Temperatures up to 1,600°C. Controlled atmospheres.
  • Gas Kilns – Box and shuttle, up to 57 cu. ft. setting. Temperatures up to 1,700°C.
  • Electric Convection Ovens – Up to 18 cu. ft. setting. Temperatures up to 600°C.
  • Electric Rotary Calciner – 6″ diameter x 6 ft. long.

Typical Tests Available

  • DTA – Differential Thermal Analysis, 1,600°C, atmosphere capable.
  • TGA – Thermogravimetric Analysis, 1,600°C, atmosphere capable.
  • STA – Simultaneous DTA/TGA, 1,600°C, atmosphere capable.
  • TDA – Dilatometric Analysis, 1,600°C, horizontal & vertical, atmosphere capable.
  • GTF – Gradient Tube Firing, 1,600°C, atmosphere capable.
  • TGDA – Drying Analysis – Simultaneous TDA/TGA, 120°C, %RH control.
  • ASTM Physical Property Measurements
  • Custom Physical Property Measurements on Request