Those strips can be anywhere from 10 to 20 BHN, the spacers did not need to be hard because they never hit the paper over and over like the letters/words did. We have five Heidelberg letter presses at work, three small and two large ones in various size machines, we use ours for scoring, perfing and die cutting.
All the Lino pigs were sold off way before I started working there, but some of the old guys gave me all the Lino pigs they had held onto for various reasons over the years, wasn't much, probably around 200 lbs. or so that I'm still sitting on for a rainy day.
There are boxes full of the spaces all around old and some new just like you show in the pic and we still use those but I can get a few random pieces and check the hardness and see what I come up with. Would be interesting to know since I might inherit them one day since the boss man know I'm a bullet caster.
Linotype usually comes in pig form or the as cast strips of words, which the word Linotype gets it name Line of type, Max BHN of new Lino is around 22, old Lino that hasn't been through the rejuvenation process will be softer, it's usually depleted of some percentage of Tin and antimony.
Individual characters etc. are usually made from Monotype which has a much higher antimony content thus making a much harder alloy, individual characters etc. that would be use repeatedly over and over were made from monotype as they would last longer and not required to be replaced as often.
Spacers can be made from brass, wood, pure lead or Lino or somewhere in between, just depends on if they were bought as new or made in-house from scrap. Spacers can also be made for aluminum blocks in various widths and sizes, these will have holes or slots in them and most will be painted black when new, but most of the paint wares off after a while.
Last edited by res45; 1 hour ago.