'Other' Constructional and Allied Systems Info & Downloads
Haynes Construction Sets
Haynes Publishers market a range of metal construction sets under their own brand name. They have parts to similar to both Meccano and Eitech Construction and are classified as Polylong(1) type set. They were manufactured in China possibly by Polylong or a successor.
Info from the Metal Constructional Systems Database for POLYLONG 
2003 to in production in 2018 and continuing
25 (see comment *1)
4.2 (see comment *2)
Bolts: pan (crosshead)
Steel with a Bright Zinc plated finish
6.5(see comment *3)
Various Sets (see separate list) from Polylong & other makers. Most parts as CONSTRUCTION  but some others. *1 Mod.1 & finer for Motor/Gear Unit.. *2 Square holes in some RCEE sets, see TRONICO [a]. *3 6.1 & 7.4 also reported.
Below there are manuals/leaflets which can be downloaded by clicking on the appropriate image.
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