What Sizes Are Available for Hollow Base Jack Products?
A hollow base jack is a small part, but it does a big job on any scaffold. It sits under the bottom standard, spreads the weight across the ground, and lets you level the whole structure with a simple turn of the thread. When you are sourcing these parts for a project, one of the first questions you will ask is: what sizes are available for hollow base jack products? The answer comes down to three dimensions—the screw rod, the base plate, and the overall adjustment range. Once you understand how these three work together, ordering the right parts becomes straightforward.
The Three Dimensions That Define a Hollow Base Jack
Every hollow base jack is described by the same set of measurements, and knowing what each one means makes it easy to compare quotes from different suppliers.
The screw rod. This is the threaded steel tube that does the adjusting. It is described by its outer diameter, its wall thickness, and its length. The outer diameter must fit inside the standard or leg it supports, the wall thickness carries the load, and the length sets how far the jack can be raised or lowered.
The base plate. This is the flat steel plate welded to the bottom of the rod. Its job is to spread the load so the scaffold does not sink into soft ground. It is described by width, depth, and thickness.
The adjustment range. This is simply the usable travel of the thread. A longer rod gives you more room to level on uneven ground, while a shorter rod keeps the part lighter and easier to handle.
Common Screw Rod Sizes
Hollow base jacks are named after the steel tube that forms the threaded rod, and the most common outer diameters are 32mm, 34mm, 38mm, and 48mm. The 38mm size is the most widely used because it matches the inner diameter of standard 48.3mm scaffold tubes and the legs of most frame and ringlock systems. Wall thickness usually runs from 3mm to 5mm, with 4mm and 5mm being the typical choices for construction-grade work. Rod lengths are available from 400mm up to 800mm, with 500mm, 580mm, and 600mm covering the majority of jobs. For example, a common configuration is a 38x5x600mm rod, while heavier-duty setups step up to a 48mm diameter.
Base Plate Sizes
Base plates are available in a range of sizes to suit different ground conditions and loads. Common plate sizes include 115x110mm, 120x120mm, 150x120mm, and 150x150mm, with thicknesses from 4mm to 8mm. Larger plates suit softer ground and heavier loads, while smaller plates are lighter and more economical. For most general construction work, a plate around 150x150mm is a safe and popular choice, and many suppliers offer it as a standard option.
How to Choose the Right Size
Match the rod to the leg. The outer diameter of the rod must fit inside the standard or leg it supports. Measure the inner diameter of your verticals before ordering, because a rod that is too small will wobble and a rod that is too large will not fit at all.
Consider the load. Heavier loads call for a thicker rod wall and a larger base plate. If your project involves heavy shoring or high stacking, go up a size rather than down.
Think about the ground. Uneven or soft ground means you will need a longer adjustment range, so choose a longer rod. On firm, level ground a shorter rod is lighter and easier to transport.
Check the surface treatment. Hot dip galvanized (HDG) jacks last far longer outdoors and resist rust in wet or coastal conditions, while electro-galvanized or painted finishes are lighter and more economical for indoor or short-term use.
The Bythai Hollow Base Jack
At Bythai Scaffolding, the Scaffolding Adjustable Hollow Base Jack is manufactured from Q235 or Q355B steel and is available with electro-galvanized, hot dip galvanized, or painted surfaces. The standard configuration uses a 38x5x580mm hollow screw rod with a 115x110x5mm base plate, weighing around 3.0kg. As a hollow base jack supplier, Bythai also produces custom sizes to match your system, with flexible MOQ for both small trial orders and large project quantities. Every jack is made in line with international EN and BS standards, so you get consistent quality whether you order fifty pieces or fifty thousand.
Ordering the Right Hollow Base Jack
There is no single “correct” size for a hollow base jack—the right choice depends on your system’s leg diameter, the loads you are carrying, and the ground you are working on. The good news is that the industry standard range is well established, from 32mm to 48mm rods and 115x110mm to 150x150mm plates, so you will almost always find a match. When you are ready to order, share your standard’s inner diameter and your expected working load with your supplier, and they can confirm the exact rod and plate size you need. If you are sourcing for a project now, the Bythai team can help you match the right adjustable base jack to your scaffolding system.