All HFT® Brass Electrode Rules are 67cm long (appx. 26") The height of ALL WELDING SURFACES ("A" in illustration below), whether for plain, pattern or in combination with Tear-Seal is 23.56mm (.928") and is maintained as a constant reference height for all rule types. The height of ALL TEAR-SEAL SURFACES is equal to 23.56mm (.928") as a constant, PLUS the height of the required Tear-Seal "step" referenced in tenths of a millimeter ("B" illustration below; 0.1mm or 1/10mm, etc.) "A" = 23.56mm (.928") constant "B" = "A" + Tear Seal Step SEAL/EMBOSS BAR "NO BEAD" TEAR SEAL "BEADED" TEAR SEAL TEAR ONLY The TEAR-SEAL "STEP" must be specified when ordering rule having a tear-seal knife edge. This "step" is normally equal to 50% of the TOTAL THICKNESS ((+).002", (-).002"), of the material being welded. Tear-Seal "Steps" are specified as: 0.1mm(.004"); 0.15mm(.006"); 0.2mm(.008"); 0.25mm(.010"); 0.3mm(.012"); 0.35mm(.014"); 0.4mm(.016"; 0.5mm(.020"); 0.6mm(.024"); 0.7mm(.028"); 0.8mm(.032"). HFT Brass Electrode Rule is also available in extra height of 30mm(1.181"); 40mm(1.575"); 50mm(1.968") as stock items in popular rule patterns. HFT rule is also available in various other specified heights on "special order." All HFT Brass Electrode Rule having a tear-seal "step" is easily identified with a "score-line" code found on one side-face of the rule. These codes are illustrated in the pages of tear-seal steps. RETURN SHIPMENTS. A return authorization number must be obtained BEFORE returning any Brass Rule shipment. Returns or Exchanges on Special Orders, or Special Shipments of "out-of-stock" items are not allowed. Exchanges for standard "in-stock" rule orders must be arranged for, and authorized within 10 days of shipment. ALL RETURN SHIPMENTS Must be re-packed to prevent the slightest damage! RETURN SHIPMENTS OF RULE, IMPROPERLY OR LOOSELY PACKED, EVIDENCING RATTLING, MOVEMENT OR VIBRATION OF RULE CONTENTS WILL BE REFUSED AND RETURNED TO SENDER AS UNACCEPTABLE. HFT BRASS ELECTRODE RULE IS PRECISION MACHINED TO EXACT TOLERANCES. ANY DAMAGE, NICKS, BURRS, DENTS, ETC., CAUSES THE RULE TO BE SCRAPPED AS UN-USABLE. ® HFT is a Registered Trademark of High Frequency Technology Co., Inc.     High Frequency Technology Co., Inc 172 Brook Avenue Deer Park, New York 11729 Tel. 1-800-342-3020     Fax. 631-242-4823     E-Mail: Info@HFTInc.com No Portion Of This Web Site May Be Reproduced Without The Written Permission Of High Frequency Technology Co., Inc.