Concrete Block Mould 400x200x200 Price: Steel, Cavities and Service Life

Concrete block mould 400x200x200 price is not a figure a supplier lifts off a shelf, because a set is a machined tool. It has a frame that carries the clamping load, core bars that form the voids, a base plate and a guiding assembly that keeps the punch square with the cavities. Change the steel, the plate thickness at the pressing face or the cavity count and you have a different product.

The block sets the starting point. A 400 x 200 x 200 mm hollow block with two cores holds a fixed amount of concrete in its walls and webs, and that geometry decides how much pressing face and how many core bars the set carries. Read the offer against the block drawing before you read the total.

What makes one mould set cost more than another?

The pressing face is where the money sits. Plate thickness at the face and the section of the frame decide how far the set deflects when the press closes. A thin plate on a light frame forms blocks on the first day and starts bowing in the middle of the pallet after a season of clamping at 31.5 MPa. Deflection shows as a block thick at the edges and thin at the centre, and vibration does not hide it.

Machining and heat treatment come next. Core bars decide whether the block releases cleanly, and a set built for a mid to high-end machine is wear-resistant alloy steel, machined on CNC to micron level and given a hardening cycle. A bar with a rough flank drags on green concrete, so the operator raises the vibration to get the block out. That costs cycle time and wears the set faster.

The 400 x 200 x 200 block: wall thickness and core layout

Wall thickness belongs in the drawing, not the sales talk. The wall and web dimensions set the concrete volume per piece, the load each cavity puts on the punch and the spacing the core bars need. Two cores or three, round or rectangular, changes the bar count and the machining hours for the same block outline.

Cavity count is limited by the moulding area. Our largest press has 1,440 x 850 mm of moulding area, and published counts for a 390 x 190 x 190 mm hollow block are 5, 10 and 12 per mould across three press sizes. A 400 x 200 x 200 mm block is longer and wider in plan, so the same area holds fewer of them.

How does cavity count meet pallet size and cycle time?

The pallet is the boundary. Our lines run 1,400 x 1,400 x 30 mm pallets and 1,350 x 1,150 x 30 mm pallets, and a set is built for one size, not both. The square pallet leaves more room for 400 x 200 x 200 mm footprints and takes more cavities. An offer that quotes a cavity count without naming the pallet is unfinished.

Cavities and cycle time multiply into output. At 15 seconds the press runs 240 cycles an hour, which is 1,920 pallets in an 8-hour shift, and at 6 cavities per pallet that is 11,520 pieces. At 20 seconds the same chain gives 180 cycles an hour, 1,440 pallets and 8,640 pieces, the bottom of the published band for a 6 cavity hollow block mould. Machines in this class are quoted at 15 to 25 seconds and 15 to 23 seconds, and a 200 mm block sits at the slow end of whichever band you buy.

Tolerance, weight, and what both do to handling

Dimensional tolerance is the line buyers skip and then argue about in the yard. In the set it is the gap between core bar and cavity wall, the flatness of the base plate and the squareness of the frame. On the pallet it appears as height variation: a stack that rocks, a cuber that grips unevenly. Ask for height tolerance per block and base plate flatness in millimetres.

Weight follows plate thickness and cavity count, and it decides how a changeover happens. A heavy set needs a hoist and a planned stop; a light one can be walked out by two men. Do not plan the change around a brick clamp, since a clamp rated at 500 kg clamping weight and 2,000 kg load is a yard tool for cured stacks.

What wears a mould out first?

Sand is the cutting tool. Crushed sand with high silica content polishes the core bar flanks and the pressing face, the block edge starts to burr and the face loses its skin. A plant running river sand and one running crushed stone dust will not get the same life from an identical set, so a life figure quoted without an aggregate description is worth little.

Vibration force is the second driver. A 280 kN exciter on one of our large machines and a 220 kN exciter on the next size down push concrete into the cavity at 3,800 to 4,500 times a minute, and every cycle sends that load through the frame and the core bars.

The third driver is the operator, and fixing it costs nothing. A set wiped at every shift change, with concrete cleared from the pressing face and release agent reapplied, holds tolerance longer than one left with a skin of concrete. Cleaning is minutes of work that moves the pieces per set figure.

Cost per block from the mould, and when a second set pays

Mould cost per block is one division: the price of the set divided by the pieces it makes before it loses tolerance. Both halves can be asked for. The pieces number depends on your aggregate and your cleaning routine; the set price depends on steel, plate thickness and cavity count. Run the division per set and add core bar replacement to the numerator, or the cheapest set shows the lowest cost on paper and the highest in year two.

A second set is a downtime argument. Every changeover takes the press out of the cycle, and a line running 15 to 25 second cycles loses pallets for as long as the change takes. If you make more than one block type, or a wear repair would idle the line, a spare on the floor removes the wait, and a pallet feeder returning an empty pallet in about 13 seconds shows how tightly the line is paced. The second set pays when the pallets lost over a season cost more than the set.

Five points to demand in every mould offer

A set cut and welded to the right outline and a set machined from wear-resistant alloy steel reach the same block size and behave differently in year two. These five items separate them during the enquiry.

• Steel and hardening: name the steel, the hardening cycle and the hardness at the pressing face and on the core bar flank, in writing.
• Plate thickness at the pressing face and the frame section, with the deflection expected under full clamping load.
• Cavity count tied to a named pallet, 1,400 x 1,400 mm or 1,350 x 1,150 mm, and to a drawing that shows wall thickness and core layout.
• Tolerance figures: block height variation across one pallet and base plate flatness, both in millimetres.
• Wear parts: which items are replaceable, core bars, base plate, guiding assembly and positioning mechanism, and whether the frame can be re-machined.