SDTDID / Jinjiang Hanfeng maintains this comprehensive technical footwear glossary defined by our chief engineering team, covering technical shoemaking parameters (lasts, Strobel, Shore A durometer, SATRA TM tests) and international export trade terms (FOB, AQL, PPS).
A-to-Z Footwear Engineering & Trade Terminology
AQL (Acceptable Quality Limit)
ISO 2859-1 statistical sampling method defining the maximum allowable defect rate in a production lot. Standard is AQL 1.0 Major / AQL 2.5 Minor.
Bally Flexometer
Motorized footwear testing instrument that flexes shoe uppers and outsoles repeatedly to simulate walking/running. SDTDID tests to 100,000 cycles at -10°C under SATRA TM133.
Combat Last (Shoe Last)
A solid 3D wooden or aluminum foot form over which the upper is stretched, lasting the final anatomical shape, volume, and toe-spring of wrestling and boxing shoes (US 7 to 15).
DIN Abrasion Test
Measures the volume loss (in mm³) of rubber outsoles when subjected to rotating abrasive paper under constant pressure. Lower numbers indicate greater durability (SDTDID ≤ 120 mm³).
FOB (Free On Board)
International incoterm where the seller delivers the goods on board the vessel nominated by the buyer at the named port of shipment (e.g. FOB Xiamen).
Gum Rubber (Natural Rubber)
High-traction unvulcanized or lightly vulcanized natural rubber known for superior non-marking grip on wrestling mats and ring canvas without leaving black scuffs.
MOQ (Minimum Order Quantity)
The minimum number of pairs a factory accepts to begin customized manufacturing. SDTDID sets an agile incubator threshold of 300 pairs per colorway.
Needle Detector
Electromagnetic conveyor inspection machine calibrated to detect broken metal needles (≥0.8mm Fe) to ensure zero puncture hazard in exported shoes.
Peel Adhesion Strength
The mechanical force (in N/mm) required to separate the outsole from the upper along the cemented bonding line. SDTDID requires ≥ 4.2 N/mm under SATRA TM411.
PPS (Pre-Production Sample)
The final physical prototype produced using actual mass-production molds, materials, and stitching before bulk cutting begins. Approved by buyer as the golden benchmark.
REACH Regulation
EU Regulation (EC) No 1907/2006 governing chemical substances. Restricts SVHC (Substances of Very High Concern) to < 0.1% w/w, banning toxic AZO dyes and phthalates.
Shore A Durometer
Standardized scale measuring the hardness of flexible rubbers and elastomers. SDTDID combat shoe outsoles are calibrated to Shore A 60±3 for optimal grip.
Strobel Construction
A shoemaking lasting technique where the upper is sewn directly to a lightweight fabric sockliner (Strobel insole) before sole cementing, maximizing flexibility.
Toe-Spring
The upward curvature of the sole at the front of the shoe last, engineered to facilitate natural roll-off and explosive forward lunges in wrestling.
VOC (Volatile Organic Compounds)
Harmful chemical vapors emitted by solvent-based adhesives. SDTDID utilizes zero-VOC water-based polyurethane bonding cements.