Technical specifications of the 4 Extension Screw Set
Specifications:
- Length: 19.1 cm
- Width: 10.2 cm
- Weight: 1.5 kg per screw
- Compatibility: Iron Uni Strength adjustable dumbbells / kettlebells
- Maximum load: up to 65 kg per dumbbell
- Contents: 4 long alloy steel screws
- Role: step 2 of the range, from 38 to 65 kg per dumbbell
The step that extends your dumbbells instead of replacing them
Your Iron adjustable dumbbells top out at 38 kg. You can buy a heavier pair, or you can change four screws.
This set of 4 long screws takes the capacity to 65 kg per dumbbell, or 130 kg for the pair. Same equipment, same mechanism, same floor space, with almost double the load range.
Why a longer screw, and not simply more plates
On an adjustable dumbbell, the screw is what holds the stack together and takes the bending load. Adding plates without lengthening the screw means reducing the engaged thread length exactly when the load goes up.
These screws are made of alloy steel. They clamp the full stack and remove play, that rattle which appears halfway through a set on a poorly locked dumbbell and is never reassuring at 60 kg.
Four screws, two dumbbells
The set contains four, two per dumbbell. You equip the complete pair in one order, without having to order the same item twice.
The swap takes a few moves, no special tool, and stays reversible. You can go back to the original screws if you sell or move part of your equipment.
Usage and safety tips
- Tighten fully and check the lock before every set, the check takes two seconds.
- Build the load up gradually after switching to the long configuration, the feel changes beyond 40 kg per hand.
- Do not exceed 65 kg per dumbbell, that limit covers screws and plates together.
- Use protective flooring, a 65 kg dumbbell dropped on the floor does not forgive.
Unique benefits of the 4 Extension Screw Set
- From 38 to 65 kg per dumbbell without buying a new pair.
- Alloy steel, firm clamping and no play under heavy load.
- Four screws, the complete pair equipped in one order.
- Reversible, the original screws stay usable.
Frequently asked questions
What does the 4 screw extension set contain?
4 long alloy steel screws, 19.1 cm long, 10.2 cm wide and 1.5 kg each, so two per dumbbell, compatible with Iron Uni Strength adjustable dumbbells and kettlebells.
What are the long screws for?
To take the capacity of the Iron adjustable dumbbells from 38 to 65 kg per dumbbell, so 130 kg for the pair, with the same equipment and the same floor space. This is step 2 of the range.
Why a longer screw rather than more plates?
It is the screw that holds the stack and takes the bending loads: adding plates without lengthening it reduces the engaged thread length. The alloy steel screws clamp the full stack and remove play and rattle mid set.
Is the change reversible?
Yes, it takes a few movements with no special tool, and the original screws remain usable.
What safety advice applies?
Tighten fully and check the lock before each set, build the load progressively after switching to the long configuration, do not exceed 65 kg per dumbbell (screws and plates included), and use protective floor tiles.
