Unless otherwise agreed at the time of enquiry and order, the specifications like size, length, straightness and related tolerances shall be as per following tables
|Supply Condition||Profile||Size (MM)||Length (MM)||Cut-to-Length (MM)|
Length Tolerance for bars is 50 mm and for Cut-to-length is 1 mm
|Centerless Peeled||Tolerance Class|
|Drawn||-||-||-||R||R||R, H, S||R, H, S|
R = Round; S = Square; H = Hexagon
The ranges are all on negative side, that is, +0.00. For a 20mm bar of tolerance class h9 with a tolerance range of 0.052, the tolerance is -0.052/+0.00.
The general supply tolerances are shown in the following table.
|Rounds||0.50 MM over 1 metre|
|Squares and hexagons||1.00 MM over 1 metre|
The preferred method involves supporting the bar on a suitable surface to eliminate or minimise sagging. If a 1 metre long straight edge is placed on the bar at any position, then the maximum gap between the bar and straight edge is measured by a suitable means such as inserting feeler gauges. The bar is deemed straight if the gap is less than that is accepted ass per General Delivery Conditions
The standard also describes a dial gauge method as an alternative to the gap measurement method. The bar is placed on a surface table, resting on V-Blocks, which are placed at a distance of 1000 mm. the dial gauge reading in between any two such blocks is the bar straightness reading.
The standard states that the maximum deviation from "out of round" shall not be more than half the specified tolerance but never above the upper limit of the tolerance.
|Size (MM)||Tolerance Class|
|over 6 up to 10||0.009||0.015||0.022||0.036||0.058||0.090||0.090|
|over 10 up to 18||0.0011||0.018||0.027||0.043||0.07||0.110||0.180|
|over 18 up to 30||0.013||0.021||0.033||0.052||0.084||0.130||0.210|
|over 30 up to 50||0.016||0.025||0.039||0.062||0.100||0.160||0.250|
|over 50 up to 80||0.019||0.03||0.046||0.074||0.120||0.190||0.300|
|over 80 up to 120||0.022||0.035||0.054||0.087||0.14||0.22||0.35|