Straight merge marking block for 1D, 1.5D and 2D mandrel bends
Marks the cuts for merging a bend into a straight tube, where the straight carries on in line with the outlet of the bend. It comes as two blocks, one for the bend and one for the straight tube. Each marks its own half of the joint, and because the two blocks share the same curved face, the two cuts meet on one seam.
Both pieces are the same tube size, and the merged outlet is one round outlet of that size.
Which version do I need?
Pick your tube size, then the radius of the bend you are merging: 1D, 1.5D or 2D. The number is the centreline radius of the bend as a multiple of the tube's outside diameter (the table below gives each in millimetres). To make a Y from two bends instead, see the Y merge cutting block.
These blocks are sized for OD tube: mandrel bends sold by their outside diameter. They don't suit SCH10S weld elbows, which are made to a different bend radius.
How it works
Close the bend block round your bend and the tube block round the straight tube. Each block is two halves held together by magnets.
Scribe along the curved face of each block where it meets the tube, on both halves.
Take the blocks off and cut both pieces on the lines.
The two blocks snap together on their curved faces, so you can sit the cut pieces back in and check the joint before you tack.
Specification
In the box: a bend block and a tube block, each in two halves (four pieces)
Marks: the merge cut on the bend and the matching cut on the straight tube
Bend radius: 1D, 1.5D or 2D, chosen when you order
Joint: the two blocks nest on a curved face and snap together with magnets
Halves: held together by magnets and lined up by locating pins
Markings: size label
Material: plastic
Made: to order in our UK workshop
Sizes
Size
Tube OD
1D bend radius (CLR)
1.5D bend radius (CLR)
2D bend radius (CLR)
1.5"
38.1 mm
38.1 mm
57.2 mm
76.2 mm
1.75"
44.45 mm
44.45 mm
66.7 mm
88.9 mm
2"
50.8 mm
50.8 mm
76.2 mm
101.6 mm
2.25"
57.15 mm
57.15 mm
85.7 mm
114.3 mm
2.5"
63.5 mm
63.5 mm
95.3 mm
127 mm
2.75"
69.85 mm
69.85 mm
104.8 mm
139.7 mm
3"
76.2 mm
76.2 mm
114.3 mm
152.4 mm
3.5"
88.9 mm
88.9 mm
133.4 mm
177.8 mm
4"
101.6 mm
101.6 mm
152.4 mm
—
4.5"
114.3 mm
114.3 mm
171.5 mm
—
5"
127 mm
127 mm
—
—
5.5"
139.7 mm
139.7 mm
—
—
6"
152.4 mm
152.4 mm
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—
Need a size or radius that isn't listed? Get in touch and we'll quote it.
