If you don't mind me asking was your cost less than buying a comparable unit? The price of steel seems so high I only build out of scrap which ends up that I can only make odds and ends.
Grader 4'-6" long, 5' wide ( inside) 575 lbs
Notes
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Lift Arm Braces 28" center to center. Alter to fit Quick Hitch if necessary.
Upper Cross Braces 2' apart
Blade Mounts 2' apart, first blade mounted 10" back, front of Blade Mounts are 3/4" below runners
3" X 3" triangles cut from bottom corners of sides for runner angles
1/2" Grade 8 bolts and extra long nuts for tail gate stop pins
swinging tailgate up and forward to hang insde against stops is like box blade ( sort of )
swinging tailgate up and back to hang behind stops allows use like push blade in reverse
Steel
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Standard lengths - Bought and picked up at steel supply house, They make one cut at no charge
3/8" X 12" steel plate 20' (2/10') $210
2 sides, 6pcs 6" X 3" for hitch clevises, tail gate
3/8" X 2" steel bar 10' $25
2 runners
2 1/2" X 1/4" Square tube 24' (2/12') $115
2 upper cross members, top link verticle and angle braces, 2 lift arm braces
4" X 4" X 3/8" angle 10' $69
2 cutting blade mounts
1 1/2" schedule 80 blk iron pipe 10' $46
hinge pin for tail gate ( used 3 short pieces of 2" sched 40 I had for hinges )
Total Steel $465
Then add for the cutting edges.
Edit: Would save $100 if I left tail gate off.