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  #16  
Old 15-04-19, 03:29 AM
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dumdum dumdum is offline
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Hi all

Approaching things from someone with an interest in how things are made, I once recall speaking to a retired jeweller who said that the "lines" you get on lugs on cap badges and the like are due to badly worn (or rusty) drawplates.

His comment was also that badges with a flat back (often seen on lapel badges and the like) that are a little "rough" can be put down to heavy scarring (from less than careful use) on the "head" of the hammer that strikes the badge.
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  #17  
Old 15-04-19, 09:24 AM
Neibelungen Neibelungen is offline
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From a manufacturing perspective, it's unlikely that the finished stock for sliders is extruded.
Rather, the raw square or round bar stock is initially extruded (pushed under extreme presure of about 250 to 1000 tons while in a red hot state through a conforming die).
It would then be anealed and set through either a rolling mill to dimension it (or flatten if round stock) before being sent through a draw plate if a precise profile or dimensional shape was required.

Typically complex 3d shapes like H beams or 'L' section are extruded directly to finished shape, the rest would be produced as round or rectangular bar which would be processes in a far less demanding (force and temperature) method.
Rolling mills can work with long straight length or continious coil, and apart from annealing, don't require complex hydraulic forces as the mechanical force is basically compressive screw pressure and the rolling action provides the mechanical power to move the object through.
Draw benches can be hand or mechanical power and are graduated down to size reducing the force required to relatively small steps.
final stock material would be in long strips or coils and these would then pass through a cropping machine (usually onsite or subcontracted) to produce end profiles (round on one side and flat on the other side of the blanking die) on half of each part. As it progresses, the flat finishes the previous piece and the round crops the start of the next.

Blanking would require much more force and leave a rim and a lot more waste material, but could work with wider stock, cropping them horizontally across a strip, either individually or as a gang.
End bending can be built into the cropping or blanking dies or a simply jig in a fly press to put the bend into a fixed position.
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  #18  
Old 15-04-19, 10:55 AM
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Luke H Luke H is offline
 
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Quote:
Originally Posted by Neibelungen View Post
From a manufacturing perspective, it's unlikely that the finished stock for sliders is extruded.
Rather, the raw square or round bar stock is initially extruded (pushed under extreme presure of about 250 to 1000 tons while in a red hot state through a conforming die).
It would then be anealed and set through either a rolling mill to dimension it (or flatten if round stock) before being sent through a draw plate if a precise profile or dimensional shape was required.

Typically complex 3d shapes like H beams or 'L' section are extruded directly to finished shape, the rest would be produced as round or rectangular bar which would be processes in a far less demanding (force and temperature) method.
Rolling mills can work with long straight length or continious coil, and apart from annealing, don't require complex hydraulic forces as the mechanical force is basically compressive screw pressure and the rolling action provides the mechanical power to move the object through.
Draw benches can be hand or mechanical power and are graduated down to size reducing the force required to relatively small steps.
final stock material would be in long strips or coils and these would then pass through a cropping machine (usually onsite or subcontracted) to produce end profiles (round on one side and flat on the other side of the blanking die) on half of each part. As it progresses, the flat finishes the previous piece and the round crops the start of the next.

Blanking would require much more force and leave a rim and a lot more waste material, but could work with wider stock, cropping them horizontally across a strip, either individually or as a gang.
End bending can be built into the cropping or blanking dies or a simply jig in a fly press to put the bend into a fixed position.
Fascinating as always, thank you Neibelungen.

Can I ask, do you know what process is used to make AA sliders as they’re often found with irregular tips similar to ‘extruded’ sliders?

Thanks,

Luke
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Last edited by Luke H; 15-04-19 at 11:03 AM. Reason: Added pic
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  #19  
Old 15-04-19, 05:11 PM
Neibelungen Neibelungen is offline
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Aluminium, being rather soft and ductile isn't the best material for making sliders, so it's likely to be cut with a rounded end from rod or thicker bar stock and then rolled or pressed into the slider form to give it a lot more stress deformation stiffness.
It's much easier to extrude because of the low melting point, but it would still be an expensive over-engineered process for a basic shape.
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  #20  
Old 15-04-19, 07:05 PM
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The material the sliders were made from was called flat rolled bar brass & iron when i started work, i don't think it was until the mid 90's we started to get all true sided quality bar and angle from Germany ?that we all take for granted these days.
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