A classifier is a screen that sits over a bucket or pan and keeps rocks out of the material you process. Start with one coarse screen of about 1/2 or 1/4 inch. Add finer screens later if you sluice, or if you want to separate fine gold from black sand at home.

This list is desk research from maker product pages and catalogs, checked October 5, 2026. Nobody at Backyard Prospectors has used these classifiers, and no recovery rates are claimed.

Quick picks

Pick Best for Openings (maker) Fit and size (maker) Build (maker)
ASR Outdoor DEEP 1/4" (Amazon search) Heavy first screen 1/4 in (also 1/2 and 1/8 in) 13 1/4 in top, 10 in bottom, 6 in deep Polypropylene, two handles
Sluice Fox 13 1/4" (#12) Single meshes for a custom stack #2 to #100; link is #12 13 1/4 in; fits atop a 5-gallon bucket Polypropylene, 303 stainless mesh
Keene CS sieves (Amazon search) Published mesh range .50 in (CS2) to .01 in (CS100) 14 in top, 11 in bottom, 4 3/4 in high Plastic, woven stainless mesh
Garrett 14" Sifter/Classifier (Amazon search) Pairing with a 14 in pan 7/16 in square holes 14 in; fits over a 5-gallon bucket Plastic, stackable
Gold Cube Golden Rule (Amazon search) Fine concentrates 16 sizes, #4 to #400 One ring and two jars Stainless steel screens

ASR Outdoor DEEP Stacking 1/4" Screen: best heavy first screen

ASR Outdoor calls these “six inch deep plastic stackable sifting screens with built in handle.” The maker lists 1/2-, 1/4- and 1/8-inch openings, a 13 1/4-inch top, a 10-inch bottom, a 6-inch depth and 4 inches of space between screens when stacked. ASR says they sit on a 5-gallon bucket and work with its stainless mesh classifiers, and that the depth is meant to move more material than a shallow screen.

Trade-offs: At 1/4 inch it is a roughing screen, not a fine-gold sorter. When checked on October 9, 2026, the Amazon listing for the 1/4-inch screen was not sold by Amazon or by a store confirmed as ASR’s own, so the link is a search.

Search Amazon for ASR Outdoor DEEP Stacking 1/4-inch Classifier

Sluice Fox 13 1/4" Gold Classifier: best for building a stack

Sluice Fox’s deep classifier is 13 1/4 inches across, fits atop a standard 5-gallon bucket and stacks with others. The maker says it is made of polypropylene with 303 stainless steel mesh, and it sells single screens from #2 to #100 mesh plus five-packs. That makes it easy to buy just the sizes you need.

Trade-offs: Each listing is one mesh size, so check the number before you buy. The Amazon link goes to the #12 mesh in black.

View the Sluice Fox 13 1/4-inch Gold Classifier (#12) on Amazon

Keene Classifying Sieves: best documented mesh range

Keene’s catalog lists eight sizes, from CS2 at .50 inch down to CS100 at .01 inch, and gives a 14-inch top, 11-inch bottom and 4 3/4-inch height. Keene says the sieves are molded in the USA with heavy-duty woven stainless steel mesh, fit over most 5-gallon buckets, and can be stacked for multi-stage concentration. Its advice is to “classify your material before processing it through your sluice box, concentrator, or gold pan to avoid losses caused by unwanted larger materials.”

Trade-offs: An Amazon lookup did not find Keene’s sieves when checked, so the link is a search.

Search Amazon for Keene classifying sieve

Garrett 14" Sifter/Classifier: best simple screen for a 14-inch pan

Garrett’s Sifter/Classifier, part 1650200, is a 14-inch plastic screen with 7/16-inch square exit holes that fits over a 5-gallon bucket. Garrett says it works wet or dry and is stackable.

Trade-offs: Punched 7/16-inch holes make it a coarse screen only. Garrett’s Gold Pan Kit already includes a 14-inch Sifter/Classifier, so kit owners may not need another.

Search Amazon for Garrett 14-inch Sifter/Classifier 1650200

Gold Cube Golden Rule: best for fine concentrates

The Golden Rule is a small classifier for concentrates rather than a bucket screen. Gold Cube says it “can perform 16 size classifications starting with #4 mesh all the way to #400 mesh,” using one ring, two jars and swappable stainless steel screens. The Pro Pack includes all 16 screens; the Clean Up Pack includes #16, #30, #50 and #100.

Trade-offs: It handles small amounts of concentrate, not buckets of gravel. Use it after a coarse screen and a pan or sluice.

Search Amazon for Gold Cube Golden Rule classifier

Convert the opening without guessing the mesh basis

The working converter above keeps three records separate: an opening you enter, a named maker or standard reference, and ideal square-wire geometry. The classifier comparison retains its October 5 research date; the converter’s named references were checked October 16, 2026.

A direct 1/4-inch entry converts to 6.35 mm because an inch is exactly 25.4 mm. That arithmetic does not certify the hole size of a physical screen. For ideal, balanced square woven wire, opening in mm = 25.4 ÷ actual count per linear inch − wire diameter in mm. An unspecified mesh label or missing diameter cannot supply an opening; the tool leaves it unknown.

The current Keene CS8 page describes .130-inch stainless steel mesh. The converter treats that text as a manufacturer nominal size, giving 3.302 mm as a numerical conversion. Gilson’s ASTM E11 reference instead lists No. 8 at 2.36 mm. Choosing one does not select the other, establish the count of wires in your screen, or certify an unmarked classifier.

The ASR Outdoor page lists separate 1/2-, 1/4- and 1/8-inch variants; the named 1/4-inch record converts only that stated size. A standard’s nominal metric aperture is also a different basis from an exact inch calculation. For example, Gilson lists an ASTM 1/4-inch designation at nominal 6.3 mm; the mathematical conversion of an entered 1/4 inch remains 6.35 mm.

Use the actual screen’s measurement, maker document or certificate for its tolerance and construction. The ideal square-wire diagram is drawn only when both actual count and wire diameter are recorded. It is not a punched-plate model or evidence of particle passage, throughput, gold recovery or bucket fit. CSV and print retain the entered values, source basis and unresolved fields.

Mesh sizes in inches

Keene publishes the following nominal sizes for its own CS series. These rounded maker labels are not a universal mesh-to-aperture table or an ASTM certificate:

Keene part Opening Mesh
CS2 .50 in 2
CS4 .25 in 4
CS8 .13 in 8
CS12 .08 in 12
CS20 .05 in 20
CS30 .03 in 30
CS50 .02 in 50
CS100 .01 in 100

How to choose a classifier

  • Start at 1/2 or 1/4 inch. The BLM and Forest Service panning booklet for the Kenai Peninsula suggests a “grizzly pan with 1/2-inch holes in bottom,” and Keene’s high-banker instructions aim for material of about 1/2 inch “for best recovery.”
  • Go finer for concentrates. Gold Cube describes running classified (1/8th) concentrates through its concentrator, and Dream Mat’s FAQ recommends running concentrates over a clean-up sluice. Both work better on sized material. See how to separate fine gold from black sand for the full cleanup.
  • Check the fit. Keene and Garrett list 14-inch tops; ASR and Sluice Fox list 13 1/4 inches. All four say they fit a 5-gallon bucket. ASR says its stainless mesh classifiers also fit its 14-inch gold pan.
  • Decide on depth. A 6-inch-deep screen like ASR’s holds more gravel per load; shallow screens nest more compactly.
  • Know the local rules. In Washington, the Gold and Fish rules say material collected outside the frequent scour zone must be classified at the collection site before processing, and a sluice may process only classified aggregate within the wetted perimeter.

Classifiers make the rest of your gear work better. For the next step, see the sluice box guide or the gold panning kits and pans guide . The Garrett Gold Pan Kit review explains what a single coarse kit classifier can and cannot do.

FAQ

What size classifier should I start with?

Start coarse. The BLM and Forest Service panning booklet suggests a grizzly with 1/2-inch holes, and Keene’s high-banker instructions aim for material of about 1/2 inch. ASR and Keene both sell 1/4-inch screens for a finer cut.

What does mesh number mean on a classifier?

A number needs its exact maker or named sieve standard. Keene’s CS8 nominal size text and ASTM E11 No. 8 are different records. With actual count per linear inch and wire diameter, use the ideal square-wire equation above. A label alone leaves the opening unanswered.

Do classifiers fit a 14-inch gold pan?

Some do. ASR says its stainless mesh classifiers fit both a 5-gallon bucket and its 14-inch gold pan, and Garrett’s Gold Pan Kit pairs a 14-inch Sifter/Classifier with a 14-inch pan. Check the maker’s stated diameters.

Sources