The Steel pair combines the solidity and authentic feel of non-adjustable cast-iron dumbbells with the flexibility of an expandable system. Simply loosen the thumbscrew by a few centimetres to adjust the load in seconds, without removing it. Tightening locks the plates perfectly, with no play, even on explosive movements such as the row or the bench press.
The flat side design lets you rest the dumbbells on your thighs safely. The 32 mm knurled chrome handle gives a firm, comfortable grip. The plates are held by two grooved safety pins, preventing any rattle or accidental shifting. Their square shape stops them rolling, improves stability on the floor and makes them perfect for Renegade Rows.
Specifications of the 4 to 20 kg adjustable dumbbells
- Weight range: 4 to 20 kg per dumbbell (expandable up to 65 kg with the extension kit)
- Adjustment: 1 kg increments thanks to the 2 micro-plates of 500 g
- Material: 100% steel
- Colour: black
- Handle diameter: 32 mm
- Handle length: 150 mm
- Handle finish: chrome
- Weight of the handle alone: 4 kg
- Weight of one bolt: 1 kg
- Weight tolerance: +/- 3%
- Square anti-roll shape
- Thumbscrew clamping
- Plates included (base): 2 micro-plates of 500 g + 8 plates of 2 kg and 2 plates of 1 kg allow weight adjustments between 4 and 20 kg
What is in the box
- Pair of 100% steel adjustable dumbbells 4 to 20 kg
- 2 micro-plates of 500 g per dumbbell
- Plates included to reach 20 kg per dumbbell
Adjustment to the kilo, where others skip steps
Most adjustable dumbbells impose increments of at least 2 kg. On isolation movements such as lateral raises or curls, that gap sometimes represents 15 to 20% of the working load, enough to tip a set from clean technique into compensation. The 2 micro-plates of 500 g here allow progression in 1 kg steps, a precision that concretely changes how you manage progress over several weeks.
With a starting weight of 4 kg, the pair covers both learning loads and working sets. Loaded to 16 kg per dumbbell, it gives access to all the basic upper-body exercises: bench press, one-arm row, curl, lateral raises, Arnold press. Quick thumbscrew adjustment lets you change the load between sets without breaking the rhythm of the session, something fixed dumbbells only allow at the cost of a full rack.
A system that follows your progress rather than limiting it
If 20 kg per dumbbell is no longer enough, there is no new pair to buy. The extension kit and the additional plates (sold separately) take each dumbbell up to 65 kg, i.e. 130 kg for the pair. That is the structural advantage of the steel thumbscrew format over quick-selection models, generally capped at 32 or 40 kg with no scope for growth.
This expandable logic also applies at purchase: the 4 to 20 kg pair uses the mechanism and handle of the 36 kg model with fewer plates included, which makes it the most accessible entry point in the adjustable dumbbells range without compromising build quality.
Comparison of the three models
| Model |
Load range |
Increment |
Max extension |
Weight per dumbbell |
| HR-36 |
5 to 36 kg |
2 kg |
65 kg |
36 kg |
| HR-20P |
4 to 20 kg |
1 kg |
65 kg |
20 kg |
| HR-36P |
4 to 36 kg |
1 kg |
65 kg |
36 kg |
