Test kit to facilitate monitoring of wheel stud and stud hole quality, also to determine the correct nut type for use with the wheel. Checkthread is used when servicing wheels to help raise awareness of the importance of wheel security to highlight problems in order to reduce the risk of accidents.
The Checkthread kit is a handy set of tools designed to facilitate the monitoring of wheel stud quality and stud hole integrity, as well as to determine the correct nut type to be used with the wheel. The product, developed in 2012, should be used when servicing wheels, to help raise awareness of the critical nature of wheel security, its fundamental correlation with the quality of studs / stud holes and to highlight problems to reduce the risk of accidents occurring
Checkthread kit use
The tool kit contains four sizes of thread tester, a Stud Hole Elongation Tool (SHET) and a spherical / conical (SPH/CON) stud hole seat tester.
Thread tester - in M18, M20, M22 and Scania standard thread sizes. The testers can quickly highlight problems with the stud thread that are not necessarily obvious under initial visual inspection, such as stud stretching, distortion, damage, dents, cracks and corrosion - all of which can lead to poor wheel security and potential wheel detachment.
The user should use finger pressure ONLY to screw the thread tester down the length of the stud thread. If the tester has strong resistance or stops entirely before the thread ends, the stud thread should be inspected for elongation and damage. Remedial action should be taken to review or condemn/replace the stud in line with company wheel safety policies and procedures.
It is recommended that the thread tester is used on every stud at the point of wheel servicing and/or at regular intervals in line with company vehicle service policy, however some companies choose to use the thread testers as a 'spot check' quality test for studs, or test a portion of the studs as standard such as two studs per wheel.
SHET tool - in size 21mm, 24mm and 26mm. The SHET tool element of the Checkthread kit is used for identifying elongation and damage to wheel stud holes. Elongation and damage can occur over time as the stud creates friction/heat against the wheel rim when the wheel rotates. The severity and speed of damage can be amplified with incorrect wheel fitment and cause melting, corrosion and elongation to the stud hole which can compound to result in wheel detachment.
The user should push the SHET into the stud hole to the depth of the corresponding size and if significant daylight can still be seen through the hole or there are clear signs of damage, the wheel should be evaluated and considered for replacement in line with company wheel safety policies and procedures.
SPH/CON tool - is used for determining the type of stud hole seat on a wheel rim, between a spherical or conical type, in order to ensure the user is aware of the correct wheel nut to use when fitting the wheel. Using the incorrect wheel nut to fit a wheel can wrongly disperse or reduce the clamp force, which can result in the nuts coming loose.
After using the SHET tool to test the wheel rim for damage and elongation, the user should push each side of the SPH/CON tester against the hole entrance and judge which side rests most flush to the hole in order to distinguish the type of stud hole surface-seat. If in doubt, the user should refer to the vehicle technical user manual.
Companies should use Checkthread® when servicing wheels and are encouraged to act responsibly by having in place sound policies and procedures to monitor wheel security and to take action to locate and minimise/eradicate underlying problems that can result in accidents occurring. It has been proven that poor quality, stretched, damaged or ill-fitted studs can be a cause of loose wheel nuts and/or a wheel detachment. Likewise, if the quality of the wheel itself, particularly of one or more stud holes, is below the required standard, the security of the wheel can be heavily compromised.
It should be noted that any specific manufacturer's instructions on wheel fitment, torquing and servicing procedures should always be strictly adhered to.