I always encounter various English vocabulary of scaffolding components at work. The classification is so small and it makes me a headache. Hereby I concluded some general English expressions referred to Google Wikipedia for your reference.

#1 Ledger：a horizontal brace

#2 Toe Board：A roofing toe board is one of the most basic pieces of safety equipment a roofer can use. A toe board is a long piece of 2'x4' ( a 2x4) wood nailed horizontally along a roof in various locations.

#3 Swivel Coupler：rotary buckle

#4 Standard：the upright component with connector joins

#5 Scaffolding Tube/ scaffolding pipe：the pipe used to erect the scaffolding mainframe

#6 Base Jacks： load-bearing base for the scaffolding

#7 Clip：clamp

#8 Hook on Board | battern | Scaffolding Plank：springboard（A board trampled by an operator），also called platform.

#9 Trapdoor：Trapdoor, skylight (for workers to enter the operating platform)

#10 Connector：connecting pieces

#11 Access Ladder：access ladder

Other expressions

#12 Diagonal Bracing

#13 Cross Bracing

#14 Adjustable Leg

#15 Catwalk

#16 Bracket

#17 Coupler：a fitting used to join components together

#18 Scaffold Tie：used to tie in the scaffold to structures