Nuts and Bolts Sorting Puzzles: A Beginner-to-Expert Guide

By the Ouleiya team · September 27, 2026

What a nuts and bolts puzzle is

A nuts and bolts sorting puzzle takes a familiar idea, sorting colored pieces into matching stacks, and puts it on a workbench. Instead of tubes of liquid or stacks of balls, you have upright threaded bolts, each holding a few colored hex nuts. You unscrew nuts from the top of one bolt and screw them onto another, and the goal is to end with every bolt holding a single color.

Under the hood it belongs to the same family as liquid sort and ball sort puzzles. The pieces are stacks, you can only touch the top of a stack, and you can only place a piece on an empty stack or on a matching color. The physical theme makes the rules intuitive: of course you can only take the top nut off.

This guide uses our game Bolt Sort for examples. In Bolt Sort each bolt holds four nuts, matching nuts on top of a bolt move together as a group, and as many of the group move as there’s room for on the target.

Beginner: learning the rules by feel

Tap, lift, place

Tap a bolt and its top nut lifts off. If the nuts just beneath it are the same color, they come along too. Tap a second bolt to screw the group on. The move works if the target bolt is empty, or if its top nut matches your color and it has room.

Only part of a group may fit

If you’re holding three blue nuts and the target bolt has one free spot, one blue nut moves and the other two settle back where they were.

What “done” looks like

A bolt is finished when it holds four nuts of one color. In Bolt Sort it gets a small colored cap so you can see at a glance which colors are handled. A level is clear when every bolt is either capped or empty.

Beginner habits worth building

• Look at the whole board before your first move. Find where each color’s nuts are.
• Make obvious matching moves first. A nut that can go onto the same color is almost always a safe move.

Intermediate: space is the real puzzle

Once you’re past the first handful of levels, you’ll notice that colors aren’t really the problem. Space is.

Count your free slots

With four nuts per bolt and two more bolts than colors, Bolt Sort always gives you exactly eight free slots at the start of a level. On some levels those are two completely empty bolts. On others they’re spread around as gaps on top of partially filled bolts.

That difference changes how you play. Two empty bolts give you two places that accept any color. Scattered gaps are more restrictive, since each one only accepts the color currently on top of its bolt, but there are more of them to work with.

Build groups, then move them

Because matching nuts travel together, one move can shift two, three, or even four nuts at once. It’s often worth spending a move or two to stack matching nuts together first, and then moving the whole group onto its final bolt in one go.

A simple example: bolt A has a red on top, bolt B has a red on top with another red beneath it. Moving A’s red onto B gives B three reds on top. Now if an empty bolt appears, those three reds can move in one step, and you only need one more red to finish.

Don’t bury your next target

Every nut you place covers the nut beneath it. Before you screw a nut on, check what’s on top of that bolt right now. If it’s the only accessible yellow and yellow is your next goal, find another destination.

Advanced: planning a color from start to finish

Estimate the dig cost

For each color, find its four nuts and count how many nuts sit on top of each one. Add them up. A color with a low total is cheap to finish. A color with one nut at the very bottom of a full bolt is expensive, and should usually be finished last.

This is the single best habit for mid-to-late levels. It turns “which move looks nice?” into “which color can I actually complete?”

Plan backward

Pick a color and decide where it will end up. A bolt that already has two of that color at the bottom is a natural home. Then list what’s in the way and where each blocking nut can go. If every blocker has a matching destination, you’ve got a clean plan. If not, pick a different color.

Emptying a bolt beats almost anything

An empty bolt is the most flexible space on the board. If a bolt has only one or two nuts left, clearing it out is often worth more than advancing a color, because it gives you room for every color at once.

Expert: tight levels and dead ends

Tight layouts

From level 18, every third level in Bolt Sort uses a tight layout: most bolts are full, four bolts hold three nuts, and only one bolt starts empty. The eight free slots are still there, but seven of them are single gaps on top of different colors.

On tight levels:

• Keep the empty bolt empty for as long as you can. Make every matching move available first.
• Use the single gaps as parking spots. A gap on top of a green is a place to put exactly one more green, and nothing else. Look for those one-for-one trades.
• Think two moves ahead before using the empty bolt. The ideal use is to lift a group off a bolt and immediately finish something with what’s revealed underneath.

Recognizing a dead end

A position is stuck when no move creates new space and every legal move just shuffles a nut back and forth. If you catch yourself moving the same nut between the same two bolts, stop.

Bolt Sort checks each position after you move. If it can prove there’s no solution anymore, a “Jammed!” screen appears and tells you whether adding an extra bolt would save the position. You can then undo, add the bolt, or start fresh.

Using helpers wisely

You get three undos and one extra bolt per level. Experts tend to save both:

• Undo is for misclicks and immediate regrets, not for experiments. Three is not many.
• The extra bolt is strongest in the endgame, when a single color is trapped. Adding it on the first move mostly gives you more room to make a mess.

Restart is free and refills both helpers, so on a hard level it’s sometimes smarter to restart with a better plan than to limp on with no undos left.

A worked example

Here’s a small position, nuts listed bottom to top, with four nuts per bolt:

Count first. Yellow is on top of bolts 2, 3, and 4, so it’s cheap. Blue is on top of 1 and 5. Orange is mostly buried.

1. Move bolt 3’s yellow onto bolt 4. Bolt 4 now has two yellows, and bolt 3 shows orange.
2. Move bolt 2’s yellow onto bolt 4. Three yellows, and bolt 2 shows orange.
3. Move bolt 2’s orange onto bolt 3. Bolt 3 is orange, orange, and bolt 2 is down to two blues.
4. Move bolt 1’s blue onto bolt 2. Three blues.
5. Move bolt 1’s orange onto bolt 3. Three oranges, and bolt 1 shows yellow.
6. Move bolt 1’s yellow onto bolt 4. Yellow is complete.
7. Move bolt 1’s last orange onto bolt 3. Orange is complete, and bolt 1 is empty.
8. Move bolt 5’s blue onto bolt 2. Blue is complete.

Eight moves, no undo. The trick was starting with the cheapest color and letting each finished group expose the next one.

Keep practicing

Nuts and bolts puzzles reward calm, deliberate play more than speed. Bolt Sort has no timer and endless levels, with a new color every three levels, so there’s always a slightly harder board waiting when you’re ready for it.