links to kink and lock in a bunch (to hockle).
Stud-link chain isn’t welded; rather, the links
are forged as a unit. The stud (crossbar), with
hollowed ends to mate with the inside of
the chain link, is inserted into the red-hot
link, which is then hammered tight. When the
link cools, the stud is fixed in place with in-
credible strength. Minimum available size for
stud-link chain is usually^5 / 8 inch (15.8 mm).
Breaking strength of standard grade 2,^5 / 8 - inch
(15.8 mm) stud-link is 33,200 pounds
(15,060 kg), and its weight is 405 lb./100 ft.
(6 kg/m), while high-test^5 / 8 - inch (15.8 mm)
anchor chain has a breaking strength of 33,000
pounds (14,970 kg), at 382 lb./100 ft.
(5.6 kg/m). Stud-link chain should be consid-
ered only for vessels over 150 feet (45 m) LOA.
Note that it’s veryimportant that chain
under load be straight and smoothly
extended. Any kink or hockle dramatically
reduces the strength of the chain and can
result in a complete failure.
Chain for Boats
The type of chain suitable for use on boats is
short-link open chain of hot-dip galvanized
steel or 316 stainless steel. The links need to
be short so they will wrap properly around a
windlass chain wildcat(“chain gypsy”in the
United Kingdom), and only either true hot-
dip galvanized steel or 316 stainless steel
have the corrosion resistance required for
reliable use in salt water.Chain Grades
You will find references to chain “grades” (e.g.,
grade 40, grade 80, etc.). Some of these have
other, more common designations such as
“proof coil,” “BBB,” and “high test.” This sec-
tion describes the more common designations.
GRADE 30 “PROOF COIL” OR “COMMON
CHAIN” This is general-purpose chain and
common anchor chain when hot-dip galva-
nized. Made from carbon steel with a tensileChapter 23: Anchor Rode
Figure 23-1.
Stud-link chain
(Courtesy
Washington Chain
and Supply, Inc.)TABLE 23-1. GRADE 30—"PROOF-COIL" CHAIN SPECIFICATIONS
Trade Wire Wire Inside Inside Inside Inside Working Working Wgt. per
Size Diameter Diameter Length Length Width Width Load Load 100 ft. Wgt.
inches mm inches inches mm inches mm Limit, lb. Limit, kg lbs. kg/m(^1) / 8 4.0 0.162 0.90 22.86 0.29 7.37 400 180 20.4 0.3
(^3) / 16 5.5 0.218 0.97 24.64 0.40 10.16 800 360 39.4 0.6
(^1) / 4 7.0 0.276 1.19 30.23 0.50 12.70 1,300 590 62.5 0.9
(^1) / 4 † 7.0 0.276 1.00 25.40 0.50 12.70 1,300 590 66.8 1.0
(^5) / 16 8.4 0.329 1.24 31.50 0.46 11.68 1,900 860 93.0 1.4
(^5) / 16 † 8.4 0.329 1.12 28.45 0.50 12.70 1,900 860 96.6 1.4
(^3) / 8 10.0 0.394 1.33 33.78 0.57 14.48 2,650 1,200 141.3 2.1
(^3) / 8 † 10.0 0.394 1.23 31.24 0.62 15.75 2,650 1,200 148.2 2.2
(^1) / 2 † 13.0 0.519 1.50 38.10 0.81 20.57 4,500 2,040 263.7 3.9
(^5) / 8 16.0 0.630 2.12 53.85 0.82 20.83 6,900 3,130 382.4 5.7
(^5) / 8 † 16.0 0.630 1.90 48.26 1.01 25.65 6,900 3,100 388.0 5.8
(^3) / 4 20.0 0.781 2.60 66.04 1.02 25.91 10,600 4,810 552.1 8.2
(^3) / 4 † 20.0 0.781 2.20 55.88 1.09 27.69 10,600 4,810 575.8 8.6
(^7) / 8 22.0 0.906 2.66 67.56 1.25 31.75 12,800 5,810 776.1 11.6
1 26.0 1.031 2.88 73.15 1.40 35.56 17,900 8,120 1,043.8 15.5
†= to ISO Specifications