How to thread a sewing machine, wind a bobbin and change the needle

Needle systems, sizes and types, thread weights and labels, winding and inserting a bobbin, and threading the machine from memory with the presser foot up.

1. The needle: system and parts Understand

A machine needle's eye is at the point, its top fits the machine one way, and its back is cut so the hook can reach the thread: each part of the stitch cycle from Your machine.

The needle system

A needle system is the code for a needle's shape and length: the dimensions that make it fit the needle bar and reach the hook at the right height. The system almost every home machine uses is 130/705 H. SCHMETZ's 2026 pocket guide calls it the most popular needle system for home sewing machines, and its FAQ says 130/705 H suits 99 percent of home machines (SCHMETZ ABC Pocket Guide, 2026; SCHMETZ, Needle Basics Q&A). BERNINA's 735 manual decodes it: 130 is the shank length, 705 means a flat shank, and H stands for the scarf (BERNINA 735 user manual). The same needle is also labelled 15x1 H; SCHMETZ treats the two codes as the same needle. Product-specific

The exceptions are real. SCHMETZ's guide says its ELx705 serger needle and its HLx5 long-arm quilting needle are not for home sewing machines, and its FAQ notes that some BERNINA machines take a 705 B needle. Your manual names the system. Write it on the machine sheet.

The parts of a needle

SCHMETZ's guide labels a 130/705 H needle from top to bottom:

The groove and the scarf are on opposite sides. The groove faces the side you thread from, and the scarf faces the hook. That is why a needle put in backwards skips stitches, as Your machine explained, and why NMSU's maintenance guide says to insert the needle with the long groove facing the side from which you thread it (NMSU Guide C-102). Physical principle

2. Needle sizes and types

Sizes

Needle packs carry two numbers, such as 80/12. The first is the metric size, NM: the blade's diameter in hundredths of a millimeter, so an 80 is 0.80 mm across (SCHMETZ). The second is the US size. Oregon State's 4-H equipment sheet says the US numbers run from 8 (fine) to 19 (heavy). Home needles run from 60/8 to 120/19; SCHMETZ's universal needle comes in 60/8, 65/9, 70/10, 75/11, 80/12, 90/14, 100/16, 110/18 and 120/19. The higher the number, the thicker the needle. Convention

The metric number is a measurement. The US number is not converted the same way by every maker, so when two packs disagree, go by the metric number. Convention

Fine fabric takes a fine needle and heavy fabric a heavy one. BERNINA's manual puts 70 and 75 for light fabrics, 80 and 90 for medium, and 100 to 120 for heavy. Brother's CP100X manual warns that sewing heavy fabric such as denim with a thin needle (65/9 to 75/11) may bend or break the needle. NMSU adds the other side: a needle thicker than needed leaves larger holes than necessary. Product-specific

Types

Needles of the same size differ in point, eye and blade. These are the types a beginner meets, from SCHMETZ's 2026 guide:

A jeans needle is for denim and dense wovens, as SCHMETZ and BERNINA both say. Whether it sews your denim or canvas cleanly in the sample in Stitching and tension settles it for you. Test it

Most SCHMETZ needles carry two color bands on the shoulder: the top band shows the type and the lower band the size. SCHMETZ's color chart page says its universal, hemstitch, double eye and quick threading needles carry only the size band (SCHMETZ, Needle Color Code Chart). The bands are SCHMETZ's own code; other makers mark needles differently,; a loose needle from another brand is best identified by its pack. The needle finder lists the type colors. Product-specific

For the first projects in this manual, a universal 80/12 suits quilting cotton: SCHMETZ lists woven cotton at universal 70/10 to 90/14, and Brother's chart puts quilting cotton among medium fabrics at 75/11 to 90/14. Canvas for a tote takes a jeans needle, 90/14 to 110/18 by SCHMETZ's table. The needle and thread finder has a row for each fabric in this manual.

3. Changing the needle

These steps are common to the Singer, Brother and bernette manuals.

1. Raise the needle to its highest point. Turn the hand wheel toward you.
2. Raise the presser foot, then switch off and unplug the machine.
3. Cover the needle hole. Brother's manual says to cover the hole in the needle plate with fabric or paper so the old needle cannot drop into the machine.
4. Loosen the clamp screw and pull the needle down and out. Hold it as it comes free. Brother says not to apply strong force; a screwdriver from the accessory kit may be needed on some clamps.
5. Hold the new needle with the flat side of the shank to the back. Singer's, bernette's and BERNINA's manuals all give "flat side to the back" for their machines, and Brother's says the flat side faces back. That is the usual layout. NMSU's general rule covers every machine: the long groove faces the side you thread from. If your manual shows something different, follow it. Product-specific
6. Push it up as far as it goes. Brother: until it touches the stop. Singer: as far up as it goes. A needle not pushed fully up is on NMSU's list of causes of breaking needles and skipped stitches.
7. Tighten the screw. bernette says by hand. Then check that the needle does not wiggle.
8. Turn the hand wheel slowly through one full stitch. The needle should go into the hole in the plate without touching the plate or the foot.

The flat-surface check

Brother's CP100X manual gives a check for a bent needle before you put it in: lay the needle on a flat surface with the flat side of the shank down, and look at the gap between needle and surface along its length. An even gap means straight; a gap that narrows or widens means bent. Put used needles in a closed jar, not loose in the bin.

When to change it

Troubleshooting and care sets how often, in your needle routine. For this chapter, three points the sources agree on:

• Start with a new needle. On a borrowed, inherited or long-unused machine, you do not know how old the needle in it is.
• Change it at the signs of wear. SCHMETZ's guide lists shredded or broken threads, skipped or uneven stitches, puckered or damaged fabric, and a popping or clicking sound. Brother's manual lists an unusual sound and skipped stitches.
• Change it after it hits a pin. A pin strike can bend or burr the point. Janome Australia's cleaning advice names hitting something other than fabric as a reason to change.

4. Thread

The default: all-purpose polyester

All-purpose thread is a medium-weight thread sold for general machine and hand sewing. Gütermann's Sew-all, for example, is 100 percent polyester, sold for all fabrics and seams, and matched on its product page to a universal needle NM 70 to 90 (Gütermann, Sew-all Thread). BERNINA's manual says polyester thread has high tensile strength, is colorfast, and is more flexible, recommended where a strong and elastic seam is needed. One spool in a color close to your fabric covers every chapter except topstitching. Convention

The same thread goes in the bobbin. Singer's M3200 manual says to use the same thread on top and bottom; NMSU's maintenance guide says the same "unless you are creating a special effect." NMSU's checklist of machine problems lists different upper and bobbin threads among the causes of skipped stitches and puckering (NMSU Guide C-202). Convention

Cotton and topstitching thread

• Cotton thread. BERNINA's manual says cotton thread suits cotton fabrics. Singer's chart suggests polyester on synthetics and cotton on natural wovens. Brother's chart lists both for medium fabrics. Either works on quilting cotton; this manual uses polyester as the default because one spool then covers every fabric. Preference
• Topstitching thread. A heavy thread for visible stitching. Gütermann's Top Stitch is polyester, matched to a universal needle NM 100 to 120, and its page says it is used as the needle thread with Sew-all in the bobbin (Gütermann, Top Stitch). That is the main exception to "same thread top and bottom." A topstitch needle, with its longer eye, is the other half of it. Product-specific

Weight, Tex and ticket numbers

Thread labels use different numbering systems, and they run in different directions.

Coats, the thread maker, defines Tex as the weight in grams of 1,000 m of thread, so Tex 40 is a thread of which 1,000 m weigh 40 g. It calls ticket numbers "merely the manufacturer's reference numbers," with a higher ticket meaning a finer thread (Coats, Thread Numbering). The thread weight printed on home spools as "50 wt" or "40 wt" also runs backward: a WeAllSew article from BERNINA's blog says a higher weight number means a thinner thread, and that weight "is an arbitrary number and can vary between manufacturers" (WeAllSew, How to Pair Thread Weight with Needle Size). Brother's manual agrees on the direction: the smaller the number, the heavier the thread. Convention

Labels mislead in practice. Gütermann lists Sew-all as thickness "No. 100" and Top Stitch as "No. 30," yet Sew-all is the all-purpose thread. WeAllSew's pairing table matches 100 wt thread to a fine 70/10 needle. The two 100s are in different systems. A label number compares one maker's threads with each other, not with another maker's.

Your machine may set limits. Brother's CP100X manual says that machine takes 30 to 90 weight thread and not 20 weight or lower, which it says may cause the machine to malfunction. That is one maker's limit for one machine; check yours. Product-specific

Matching thread to needle

Two tests check that a thread suits a needle:

• The groove and eye. BERNINA's manual says the combination is right when the thread lies fully in the needle's long groove and passes easily through the eye. Too much room causes breaks and skipped stitches; too little and the thread scrapes and breaks.
• SCHMETZ's slide test. Thread the needle, hold the thread at about 45 degrees, and let go of the needle. If the size matches, the needle slides slowly down the thread under its own weight. If it drops, the eye is large for the thread; if it stops, the eye is small. Test it

WeAllSew's article gives a starting chart: 70/10 for 100 wt, 80/12 for 50 wt, 90/14 for 40 wt, 100/16 for 30 wt and heavier. Those weights are one practitioner's pairing, and weight labels vary by maker, so the slide test on your own thread and needle is the check. Preference

5. Winding and inserting the bobbin

The right bobbin

Bobbins look alike and are not interchangeable. A bobbin class (or the maker's part number) names a bobbin's diameter, height and shape. Singer's M3200 manual lists Singer Class 15 bobbins in the accessory kit. Brother's CP100X manual says to use the included bobbins (part SA156) "or the same type," and calls SA156 a Class 15 type bobbin. Brother's troubleshooting pages list "a bobbin designed for this machine is not used" among the causes of tangled thread, wrong tension and breaking upper thread (Brother CP100X operation manual). Product-specific

Bobbins of one class can still differ in details, such as the slit in Brother's quick-set bobbin. Use the bobbin class or part number in your manual, and buy bobbins by that name. Write it on the machine sheet. If a borrowed machine came with a jar of mixed bobbins, keep only the ones that match the ones the manual shows.

Winding a bobbin

The bobbin winder fills a bobbin from the spool. The steps are close across the manuals we read; Singer's M3200 and BERNINA UK's foundation course notes are the basis here (BERNINA UK, 325 and 335 Foundation Course notes).

1. Put the spool on the spool pin with its cap.
2. Lead the thread through the winding guide and around the pre-tension disc. Both Singer and BERNINA UK say clockwise around it.
3. Thread the empty bobbin. Pass the end through the hole in the bobbin's rim from inside, or wind it on by hand two or three times, as your manual shows, and put the bobbin on the winder spindle.
4. Push the spindle into winding position. On Singer's M3200 the spindle moves to the right; in that position the machine does not sew.
5. Hold the thread end and start the winder. Singer says to run it a few turns, stop, cut the tail close to the bobbin, and start again.
6. Wind until it is full, and no more. Singer says the bobbin rotates slowly once full; Brother's manual says to stop when it seems full and begins spinning slowly.
7. Cut the thread, push the spindle back to sewing position, and take the bobbin off.

Look at the result. The thread should lie evenly across the bobbin and feel firm. NMSU's checklist lists a bobbin wound unevenly or overfull as a cause of the lower thread breaking. Rewind a soft or lopsided bobbin; check the thread is around the pre-tension disc. Test it

Inserting the bobbin

Switch the machine off first; Singer says to turn the power off and fully raise the needle before inserting or removing the bobbin. Then follow your manual's drawing for which way the bobbin faces. Two examples show why the drawing matters:

• Singer M3200, front-loading. Take out the bobbin case by its latch, drop the bobbin in so the thread runs clockwise, pull the thread through the slit and under the tension finger, leave a 6 in (15 cm) tail, and click the case back into the shuttle. Product-specific
• Brother CP100X, top drop-in. Drop the bobbin into the built-in case so the thread unwinds counterclockwise, hold it down with a finger, and guide the thread through the slit and the tension spring, following the arrows printed on the needle plate. Product-specific

Clockwise in one, counterclockwise in the other. NMSU's checklist lists a bobbin inserted the wrong way as a cause of looping. A quick check on most machines: hold the bobbin so the thread tail hangs as the drawing shows, then pull the tail. The thread should come off smoothly with a light, even drag, and on a front-loading case the bobbin should turn in the direction the manual's arrow shows.

6. Threading the machine

Why the presser foot goes up first

The tension discs only grip the thread when the presser foot is down. Raising the foot opens them. Singer's M3200 manual says to raise the presser foot "to release the tension discs" before threading. If you thread with the foot down, the thread rides on top of closed discs instead of sliding between them. The machine then sews with almost no upper tension, and the upper thread loops and piles up under the fabric: the nest Troubleshooting and care teaches you to clear. Brother's, bernette's and BERNINA UK's threading steps all start with the foot raised. Physical principle

The needle goes to its highest point first too (Singer, Brother), so the take-up lever is at the top where the thread can enter it.

The path

Every lockstitch machine leads the upper thread through the same stations in the same order, though the guides look different. bernette's b05 manual lists them in order (bernette b05 manual, Threading the Upper Thread):

1. Spool on the pin, with the cap. bernette says the thread should unwind clockwise; Brother says to check that it unwinds as its drawing shows.
2. Through the first thread guide at the top.
3. Around the pre-tension guide.
4. Down the channel and between the tension discs. Hold the thread on both sides of the discs and ease it in.
5. Around the bottom of the channel and back up.
6. Through the take-up lever (right to left on the bernette). This is the station most easily missed. With the lever at its highest, the thread passes through its eye or hook.
7. Back down through the guides above the needle.
8. Through the needle's eye, in the direction your manual shows; the groove faces the side you thread from. Pull through about 6 in (15 cm).

Brother's manual says to follow the numbered path printed on the machine, if yours has one.

The needle threader

Many machines have a built-in threader that pulls a loop of thread through the eye with a tiny wire hook. Both bernette and BERNINA UK say to lower the presser foot to use it. Brother's CP100X manual says its threader works only with needles 75/11 to 100/16, not with twin or wing needles or decorative threads. Otherwise thread the eye by hand; a white card behind the needle helps. Product-specific

Pulling up the bobbin thread

1. Hold the end of the upper thread lightly in your left hand.
2. Turn the hand wheel toward you through one full turn, so the needle goes down and comes back up.
3. Pull the upper thread. A loop of bobbin thread comes up through the needle hole. Brother's manual describes this step as pulling on the upper thread to draw up the bobbin thread.
4. Pull the loop out until you have the bobbin thread's end.
5. Lay both threads to the back under the presser foot, as Singer's manual shows, with about 4 to 6 in (10 to 15 cm) of each.

Brother's quick-set bobbin lets you sew without drawing the bobbin thread up first; your manual says if yours does.

Unthreading

To take the thread out, raise the foot, cut the thread near the spool, and pull the cut thread out through the needle end, downward. Pulling it back up the path drags it through the guides and discs. This is our habit, not a manual's instruction. Preference

7. See it: Dana threads her machine See it

Free sources that show this chapter's material:

• SCHMETZ ABC Pocket Guide, 2026: drawings of the needle's parts and points, every needle type, and a fabric table on its last two pages.
• bernette b05 manual, Threading the Upper Thread: the threading path with each station numbered and named.
• Singer M3200 instruction manual: bobbin winding and a front-loading bobbin case in drawings, pages 6 to 9.

8. Practice: thread it three times Practice

Minimum: one new needle in, one bobbin wound and inserted, the machine threaded with the bobbin thread pulled up, then unthreaded and threaded twice more without the manual. Time: about 45 minutes. Materials: universal 80/12 needles (or the size your manual suggests), one spool of all-purpose polyester thread, two or three empty bobbins of your machine's class, the screwdriver from the accessory kit if your clamp needs one, a scrap of paper, and the manual.

1. Find the bobbin class and needle system in the manual. Write both on the machine sheet.
2. Unplug the machine and change the needle. Flat-surface check, flat side as your manual shows, fully up, screw tight; turn the hand wheel through one stitch.
3. Wind a bobbin. Check it is firm and even. Rewind if not.
4. Insert the bobbin as your manual's drawing shows. Pull the tail to check it runs smoothly.
5. Thread the top with the foot up and the needle at its highest. Thread the eye by hand or with the threader.
6. Pull up the bobbin thread and lay both threads to the back.
7. Check the threading. With the foot down, pull the upper thread toward the back: you should feel firm, even resistance. With the foot up, it should pull almost freely. If it pulls freely with the foot down, the thread is not in the discs; rethread.
8. Unthread and do it again without the manual. Twice. If stuck, look up that one station.

9. Your sewing Your sewing

10. Check your work Check your work

Criteria

• Is the needle the system your manual names, new, straight, flat side the way your manual shows, and pushed fully up?
• Does the needle clear the plate when you turn the hand wheel through a stitch?
• Is the bobbin the class your manual names, wound firm and even, and not overfull?
• Does the bobbin thread run the direction your manual's drawing shows, with a light, even drag?
• With the foot down, does the upper thread pull with firm resistance; with the foot up, almost freely?
• Can you thread the machine and pull up the bobbin thread without the manual?
• Does the machine sheet name the bobbin class and the needle system?

Worked example

Dana (fictional) has a new universal 80/12 that passed the flat-surface check, in flat side back and up to the stop. Her second bobbin is firm and even after the first was rewound. The thread runs clockwise off the bobbin, as her manual shows. Her third threading, without the manual, passed the foot-down pull check. The machine sheet reads "Class 15" and "130/705 H." Every criterion is met. Whether the needle and thread suit her cotton stays open until her Stitching and tension sample.

Common mistakes

• Threading with the presser foot down. The thread misses the tension discs and nests under the fabric. Raise the foot and rethread from the spool.
• Missing the take-up lever. The thread unthreads at the first stitch.
• A needle not pushed fully up, or in backwards. Skipped stitches and broken needles. Take it out and reinsert it.
• The wrong bobbin, one that looks the same but is not your machine's class.
• An overfull or lumpy bobbin. Rewind it; check the thread is around the pre-tension disc.
• The bobbin in upside down. The thread runs the wrong way off it. Compare with the drawing.
• Going by the US needle size alone. Use the metric number.

What is still unresolved

This chapter does not show whether your needle and thread suit your fabric, or whether your tension is balanced; The sample on the real fabric in Stitching and tension does both. When to change the needle as a routine is a question for Troubleshooting and care. If the bobbin case on your machine is damaged or a bobbin will not sit flat, that goes to a dealer.

11. Knowledge check and scenario

Checklist

• I can thread the machine and pull up the bobbin thread from memory.
• The machine sheet names the bobbin class and the needle system.
• A new needle is in, checked on a flat surface, flat side the way my manual shows, pushed fully up.
• I wound a firm, even bobbin of the right class and inserted it the way my manual shows.
• I unplug the machine before changing the needle and switch it off to thread it.
• I tried SCHMETZ's slide test with two needle sizes. (Go deeper; optional)
• I wound a second bobbin in a contrasting color for Stitching and tension. (Go deeper; optional)