Weld-On Hinge Sizes: Understanding Diameter and Length

Find the right family first

Open the product page that matches the required construction. A size from the bearing family does not automatically describe the pin or round family. Compare the product drawing as well as the photograph, especially when replacing a part whose original supplier is unknown.

You will find three common formats in the HINGETRA listings: diameter-by-length entries, longer compound size strings, and numbered models with a parameter table. Keep the complete entry in your inquiry. Do not shorten a compound string to the two numbers that look most familiar.

Show where diameter and length are measured

On your own sketch, put arrows at the ends of each measurement. State whether length means the complete assembled hinge or one section. Identify body and pin measurements separately. If the existing part is worn, record that alongside the measurement rather than treating it as the required new-part dimension.

Some entries include weight in grams. That is the mass of the hinge itself; it does not tell you what door the hinge can support. Give the supplier the door arrangement and weight separately.

Read numbered models without rounding them

These are the original values, with no unit added: the source table does not print one. Keep 11.80 as written rather than replacing it with 12. The model and D value answer different questions.

The 20 type series makes another distinction: 20-A has chamfered ends, while 20-B has right-angle ends. Their end shapes need to be identified even when you are comparing the accompanying dimensions.

Keep units and drawing symbols visible

The 20 type and 12 / 14 / 16 type tables do not print a unit. Ask for confirmation before using their values in a fabrication drawing. Where a listing explicitly gives millimetres, keep that unit. For your own dimensions, state the unit in the drawing title block or next to the value.

Symbols such as D, D-1, L, d, L-1, c and L-2 refer to positions on their own drawings. Match each symbol to its view. If your drawing uses different letters, mark the corresponding positions instead of assuming that the same letter means the same feature.

Resolve a size mismatch before ordering

• Identify the family and model or complete size string.
• Show the required dimensions on a sketch, with confirmed units.
• Label values as measured, required or copied from the product listing.
• Highlight differences from the listed entry and include the drawing revision.

For example, write “Model 12-A; please confirm the unit for D = 11.80 and review the attached installation sketch.” This gives the supplier a specific point to answer. If the required size differs, use the custom request checklist rather than editing a product table and presenting it as an existing option.