What Size Joist Hanger Do I Need? 47mm, 50mm and 6x2 Timber

Choose the hanger to match the actual width of your joist, then check the model is suitable for the joist depth, supporting material and required load. A timber described as “6x2” does not give you enough information to order a hanger on its own.

Start with a tape measure and the connection drawing, if you have one. Write down the timber width and depth in millimetres, and whether its end will meet timber, masonry or another support. Those three details will narrow the choice far more usefully than a label such as “heavy duty”.

Your five-point joist hanger size check

1. Measure the actual timber width where it sits between the hanger sides.
2. Measure the joist depth and compare it with the permitted range for the model.
3. Identify the support: timber, built-in masonry or another designed connection.
4. Check the full connector drawing, including leg height and bearing depth.
5. Confirm the fixing schedule and load data before choosing the pack quantity.

47mm or 50mm: which width should I buy?

If your joist measures 47mm across, look for a hanger specified for 47mm timber. If it measures 50mm, look for the corresponding 50mm model. The dimension that matters is the timber sitting between the hanger sides, rather than the overall width across its fixing flanges.

Do not buy a wider hanger simply because it is available. Packing an oversized connector, bending its sides or cutting it down changes the connection. Any such detail needs the connector manufacturer’s approval and the project designer’s specification.

What size joist hanger do I need for 6x2 timber?

“6x2” is a trade description. Measure the piece you are using. For example, if it actually measures 47mm wide by 145mm deep, you need a hanger intended for that width and approved for that depth and application. A piece measuring 50mm wide starts with a different width choice.

The same approach applies to 4x2 and 8x2 timber. Do not turn the inch description into a hanger order without checking the delivered timber.

What size joist hanger do I need for 4x2 timber?

Use the measured section, rather than ordering from the nominal 4x2 name. Check width and depth separately: two pieces sold under the same nominal name may have different finished dimensions. A compact mini hanger and a taller multi-truss hanger can share a width while having different connection requirements.

Compare the available mini hanger widths and standard-leg jiffy hangers against the specification for the job. The project size alone does not tell you which style is suitable.

Which hanger fits a double joist?

Measure the complete built-up member. Two 47mm-wide joists together measure 94mm before allowing for any other part of the specified assembly; a product described as a 91mm hanger is not automatically a match. Use a hanger approved for the actual combined width, depth and connection load, including the required detail for joining the members together.

Our 91mm jiffy hanger is one width option to compare, rather than a universal double-joist recommendation.

Hanger height and joist depth are different measurements

A hanger’s metal height is not automatically the depth of timber it can support. That relationship depends on its design. Some hangers have long legs, some have a compact seat and some use a particular fixing pattern for a stated joist-depth range.

Our 47mm multi-truss hanger illustrates the distinction: its technical sheet gives a 47mm width, 148mm metal height and 75mm bearing surface. Check the actual model sheet rather than treating the “150mm” wording in an older product URL as a specification.

Timber-to-timber or masonry?

A hanger selected for a timber beam connection is not automatically a masonry hanger. Timber-to-timber models use a specified connection to the supporting timber. Built-in masonry hangers have their own requirements for the wall, bearing and masonry above them. A face-fixed connection to masonry is another designed arrangement.

Compare timber and masonry designs together in our joist hangers collection, then use the hanger types guide to distinguish their support details. For engineered joists, doubled members or unusual angles, use the relevant system’s connection details.

Check the fixings before you check out

Confirm the exact nail or connector-screw specification, finish and fixing pattern. Standard wood screws are not an automatic substitute for tested connector nails. Simpson Strong-Tie explains this distinction in its connector FAQ; follow the instructions for the brand and model you are buying.

For the MTH example above, consult the MTH/340 technical data sheet and its separate fixing information. Load capacity depends on the timber grade, fixing arrangement and load direction. The right width alone does not establish structural suitability.

Ready to compare? Browse all joist hangers, and use our joist hanger nail guide to check the fixing details alongside your connector specification.