if I remember correctly Spike plating requires sheet metal and scrap metal.
actually :
8x lump of steel OR steel plating
4x chunk of steel OR 8x scrap metal OR 4x spike
also either a vehicle forge rig or a welding rig (or welder, acetylene torch, integrated toolset, etc) . you can always open the build menu “&” press “f” for filter, then “spike” that should show you all the recipes that you can craft with the word “spike” in it. If it doesn’t show up in the list you may need a specific mechanical book for the recipe. i.e. :
Book: Mechanical Mastery
Can bring your mechanics skill to 6
Requires mechanics level 3 to understand.
Requires intelligence of 6 to easily read.
Reading this book affects your morale by -1
This book takes 30 minutes to read.
This book contains 14 crafting recipes:
combat chainsaw (off), chainsaw (off), pane of reinforced glass, reinforced head light, vehicle controls, folding bicycle, duct tape, spiked plating, firearm repair kit, makeshift welder, jackhammer, recharging station, vehicle forge rig, vehicle welding rig
An advanced guide on mechanics and welding, covering topics like “Grinding off rust” and “Making cursive E’s”.
Book: Welding and Metallurgy
Can bring your fabrication skill to 7
Requires fabrication level 4 to understand.
Requires intelligence of 9 to easily read.
This book takes 30 minutes to read.
This book contains 13 crafting recipes:
pair of welding goggles, shishkebab (off), No. 9 (off), firebrand (off), Rising Sun (off), flammenschwert (aus), pane of reinforced glass, reinforced head light, spiked plating, hard plating, makeshift welder, vehicle forge rig, vehicle welding rig
A rather technical textbook that illustrates the science and technique of becoming a better welder.