We love Spitz etc. Great for going down. Not so great for going up. Cost ~£1.50
Can we find somewhere to buy the ~100 cones we need to complete our Bivvi collection?
10mm hole, wedge set by driver that passes through standard M8 thread, as used by CUCC since 1990. Not a problem if hole too deep. http://cucc.survex.com/expo/years/1990/drill.htm
via. Ukcaving forum: HKD-S (Plain steel) - M8 x 30 = 11.65+ VAT /100
Jarv Notes: Thinner walls than spits, only 1 deep ridge vs. 3 on true spit. Seems a bit of a halfway house?
Through Bolts (Aka suicide bolts)
According to Inglethief, standard is: "10mm dia. x 90mm stainless steel through bolts, norm for climbing 8mm dia. x 100mm"
Suicide bolts cheap from hardware manufac:
Q. Can we get normal hangers for these? Commercially available seem to be for 8/10mm bore.
Q. What is the strength of a bolt, wrt. diam and length? Proportional to Diam^2 * length ? Or far far more complex? Energy to drill hole should be proport. diam^2 * length.
Q. Worth getting a 6mm SDS drill bit, or using current 8mm with 'pecker / electric drill?
My feeling is that up-climbing / suicide may as well be mild steel, but stainless is best for any M8x100 etc. used to rig. So should we make it so suicide bolts = 6mm steel, all 8mm are 100mm stainless? Or risk mixing the two types for standardisation of diameter?
Costs scoped from PVRDIRECT web catalogue linked below 30-12-07
Nb: Gladiator's wire was rigged off M18s (depth unspecified), ref. The Hollow Mountain p.94