The products

Four leaves, two problems

On this page14

Tumbler spring Lock pin Which is the static half of the group Key blank Which is the scratching half Padlock part So the material answer differs by leaf Which is the same answer twice for different reasons Sorting is the other requirement Which needs the small end And a wide mouth, for fingers Oil is the fourth consideration Four leaves and one material recommendation References

The group divides on weight.

Tumbler spring

A few millimetres of light steel wire. The lightest article in the group and the one that clings hardest to a charged plastic wall.

Lock pin

A small steel cylinder, a few millimetres long. Heavier than a spring and still light enough to cling.

Which is the static half of the group

Two leaves of light steel, and 195 of the 251 containers on this shelf are plastic.

Key blank

Heavy enough not to cling, and it has a profile and a finish that a plastic wall scores.

Which is the scratching half

A jar of blanks shaken in a van marks the blanks and hazes the jar, and both matter.

Padlock part

Which spans both halves depending on what it is. A shackle is heavy and a detent spring is not.

So the material answer differs by leaf

Glass for the springs and pins because it does not hold a charge. Glass for the blanks because it does not score them.

Which is the same answer twice for different reasons

And it points at 56 of the 251 containers.

Sorting is the other requirement

A pin of the wrong length is useless, and a spring of the wrong rate is worse. One size per container is the only workable arrangement.

Which needs the small end

60 of the 251 containers are under 60 mL and 22 under 30. Which is where a set of ten pin lengths lives.

And a wide mouth, for fingers

56 containers at 70-400 and 56 at 89-400, which are the two widest common finishes on this shelf.

Oil is the fourth consideration

Lock parts arrive lightly oiled, and oil defeats an adhesive label and collects grit. Which argues against a labelled plastic jar and for glass again.

Four leaves and one material recommendation

Which is unusually simple, and the shelf offers it on a fifth of its containers.

References

The Davis Pack Supply catalog, measured 19 October 2026. The 251 containers on this shelf are 117 PET, 78 polypropylene and 56 glass, so 195 plastic against 56 glass, a little over four to one. For a small metal part the difference is practical: glass does not scratch, does not haze and does not take a static charge, and both plastics do all three.

The Davis Pack Supply catalog, measured 19 October 2026. 539 rows: 251 containers and 288 closures. This is the store-small-dry shelf, shared identically by nine groups, and the sewing notions property enumerates the inventory. 5 to 500 mL with a median of 177, with 60 containers under 60 mL and 22 under 30. 210 jars, 27 bottles, 12 tubs and pails, 2 tubes. Buyability, a snapshot: 159 of 251 available, 91 not, 1 unrecorded; 93 quote only; 65 full case only, with case packs from 12 to 6,370 and a median of 288.

Written from 18 U.S.C. 1704 and from the catalog as it stood on 19 October 2026. That section is a theft and forgery statute about keys to Postal Service locks and says nothing about containers, labeling or packaging; it is quoted because it is the federal provision that names a key. Nothing here addresses the lawfulness of making, holding or selling any key or key blank, locksmith licensing, restricted keyways, key duplication, or whether any mark has legal effect, and nothing here would assist anybody in defeating a lock. This shelf is shared identically by nine groups and the sewing notions property enumerates the inventory.