TM 9-2610-200-14 E-6 APPENDIX E: GLOSSARY (Con't) Separation   Any parting or void within the tire body structure, indicated by bubbles,   blisters, or other unusual deformation of the regular inner or outer tire surface. Setup   Premature vulcanization of a rubber compound during processing or   storage. Shoulder Radius   Small radius (generally) that joins the primary tread radius to the shoulder   contour. Sidewall   That portion of a tire between the tread and bead . Size Factor   The size factor of a tire is the sum of its section width on its measuring   rim and its outer diameter . Sizing Measuring the tire casing to determine proper matrix fit. Usually a combination of bead-to-bead, or cross section and tire circumference is used. Skid Depth (Tread Depth)   The distance, measured near the centerline of the tire, from the base of   the tread design to the top of the tread . Skiving   Removal of damaged material prior to making a repair. Slab Stock   Tread compound cut from a rubber mill in wide, thick strips. Spot Press   A heat vulcanizing unit used in spot repairs and built with a metal curing place on one side. Spreader   A device used to force the tire beads apart to give access to the inside of   the tire. Standard Rim   A rim that has been calibrated and found to meet the precise   measurements specified by the Tire and Rim Association, Inc. or, where applicable, by the European Tire and Rim Association. Stitching A hard rolling method used to both remove trapped air and improve   rubber contact for better adhesion . Tack     A term used to describe tackiness. Tempil Sticks    A type of crayon used in checking surface temperatures of various   degrees. Tread   That portion of a tire that comes in contact with the road. Tread Depth    The distance, measured near the centerline of the tire, from the base of   the tread design to the top of the tread . Tread Design    The nonskid pattern on the tread portion of the tire.