A high-collar helical spring-lock washer is a specific section of helical washer, not a generic name for every split lock washer. Its nominal size is selected to match the screw or bolt; the inside-diameter limits, outside diameter and section width then help confirm the part and the available bearing footprint. This chart shows four selected inch sizes.
Selected high-collar dimensions
The inside diameter is shown as a minimum-to-maximum range. The outside diameter is a maximum, and the section width is a minimum. Do not mix those limits with the regular-section or heavy-section dimensions in the same washer standard. A seller’s shorthand may omit the section name, so confirm the part drawing or packaging before substitution.
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Match the fastener and seating surface
Choose the nominal washer size for the fastener’s nominal thread size, not by measuring an unrelated head feature. Then confirm that the washer can sit flat and clear nearby edges, recesses and hardware. Compare its outside diameter with the available bearing area and the clearance to adjacent components. A washer that interferes with a shoulder or radius may not seat as intended.
Check the joint material and finish as well. A hardened washer can mark a softer surface; plating, coating or lubricant can affect assembly friction and corrosion behavior. Where electrical bonding, sealing or a specified preload matters, use the washer and assembly procedure named in the design or supplier documentation.
Do not treat the word lock as a guarantee
ASME notes that “lock” is a generic term historically associated with these products and does not promise indefinite resistance to loosening. A helical washer should not be treated as a universal vibration-proof solution. The joint’s clamp load, surface condition, fastener design, temperature cycling, transverse movement and maintenance all affect performance.
For a critical joint, use an engineered fastening method supported by the application requirements and the fastener maker’s instructions. Depending on the design, that may require a prevailing-torque nut, a qualified adhesive, a wedge-lock device, a positive locking feature or another validated method. Do not substitute one method based only on the appearance of the hardware.
Read the dimensions as limits
Dimensional ranges help with identification and inspection; they do not tell you the clamp force, torque, fatigue life or loosening performance of a completed assembly. Use the specified fastener grade, lubrication state and tightening procedure to determine preload. Do not calculate tightening torque from washer dimensions alone.
If a washer must be replaced, verify nominal size, section, material and finish. Check the supplier’s current drawing and stock availability; ASME explicitly notes that a dimension appearing in the standard does not mean every item is a stocked product. Retain lot or material documentation where the joint’s quality plan requires it.
When another washer style fits better
High-collar, regular, heavy and extra-duty helical washers are different series. Internal- and external-tooth washers are separate designs and should not be substituted by dimension alone. For thin panels, painted surfaces, soft materials or joints that need a broad bearing face, a plain washer or a different engineered retention method may be more appropriate.
Use the selected values as a quick cross-check, then confirm the full part identity with a supplier. The chart is not a complete reproduction of ASME B18.21.1 and does not specify material grade, hardness, coating, twist test, torque or service life.
Related references: bolt clearance-hole sizes, SAE bolt torque guidance, and ribbed-neck bolt dimensions.
Source and scope
The selected dimensions are from the high-collar table on printed page 1698 of the 31st edition of Machinery’s Handbook and were checked against the ASME B18.21.1 scope and a washer manufacturer’s product categories. ASME lists B18.21.1-2009 (R2016) as remaining in effect on stabilized maintenance. It cautions that standard dimensions do not imply stock availability and that “lock” does not guarantee permanent fixity. ASME B18.21.1 scope and status; TRUST Manufacturing washer styles.
