Repair and Diagnosis: Description and Operation
Fasteners InformationMetric Fasteners
Most of the fasteners used for this vehicle are JIS-defined and ISO-defined metric fasteners. When replacing any fasteners, it is most important that replacement fasteners are of the correct diameter, thread pitch and strength.
CAUTION:
The thread pitch (2) or the width across flats (3) may vary between ISO-defined and JIS-defined fasteners even when the nominal diameter (1) of thread is the same. Refer to JIS-TO-ISO Main Fasteners Comparison Table below for the difference.
Installing a mismatched bolt or nut will cause damage to the threads. Before installing a fastener, check the thread pitch for correct matching and then tighten it by hand temporarily. If it is tight, recheck the thread pitch.
JIS-TO-ISO Main Fasteners Comparison Table
Fastener Strength Identification
Most commonly used strength classes of metric fasteners are 4T, 6.8, 7T and 8.8. Strength class is indicated by a number or radial line(s) embossed on the head of each bolt. Some metric nuts have a punched number, 6 or 8 on their end surfaces. Figure shows different strength markings. When replacing metric fasteners, be sure to use bolts and nuts of the same strength class as or higher class than the original bolts and nuts. It is also important to select replacement fasteners of the correct diameter and thread pitch. Correct replacement bolts and nuts are available as SUZUKI spare parts.
Metric bolts and nuts: Strength class numbers or marks (The larger the number, the greater the strength).
Standard Tightening Torques
Each fastener should be tightened to the torque specified in each section. If no torque description or specification is provided in the relevant section, refer to the following tightening torque chart for the applicable torque for each fastener. When a fastener of greater strength than the original one is used, use the torque specified for the original fastener.
NOTE:
- For flanged bolts, flanged nuts and self-locking nuts of the 4T and 7T strength classes, add 10% to the applicable tightening torques given in the following chart.
- The following chart is applicable only where the fastened parts are made of steel or light alloy.
Tightening torque chart
