Home　>　Screw Square　> Screw Trouble Q & A use as just reference. For inquiries, please click here . When you turn the screw, it spins idle. The head of the screw / bolt was broken during tightening. The size is correct, but the screws do not fit. It becomes impossible to screw in on the way. The screws come loose even though I tightened them properly. The head of the tightened bolt flew away. The screw does not fit in the screw hole. The cross hole on the screw head was crushed and could not be removed with a screwdriver. The hexagonal hole was crushed and could not be removed with a hexagonal wrench. The screw rusted in a short period of time. The screw does not fit. Stainless steel screws gnawing and seizing when tightened. I want to prevent tampering with screws. What is the length of the threaded part of hexagon bolts and hexagon socket head cap screws? I want to electroplat the hexagon socket head cap screw, is that okay? About the screw manufacturing method When you turn the screw, it spins idle. The male or female thread may be crushed. If it is a driving nut or anchor, it may not be attached properly to the base material. Check if the anchors are rotating together. If the female screw is crushed, re-screw it with a repair material or use a screw with a diameter larger than the one currently used. If the male screw is crushed, replace it with a new one. The head of the screw / bolt was broken during tightening. It is possible that the tightening force during tightening is greater than the maximum tightening force of the screw. Do not apply more force than necessary. The size is correct, but the screws do not fit. It becomes impossible to screw in on the way. Is there anything stuck between the threads? Or are there some threads that are crushed? In either case, it is considered that there are dents such as tool scratches on the thread when manufacturing the screw. Be careful not to forcibly screw it in as it may damage the thread on the other side. The screws come loose even though I tightened them properly. Have you removed the screws many times? In that case, it is possible that the thread is scraped and thinned due to the frictional stress during tightening. If you use the screw repeatedly, replace it after using it a certain number of times. If the screw is loosened when using it in a vibrating part, it is effective to use a lock nut. The use of the anti-loosening agent Loctite is even more effective. There are "Loctite" and "Precoat" in our products. Please use the inquiry email for inquiries regarding loosening bolts. The head of the tightened bolt flew away. It is thought that the cause is brittle fracture or stress higher than the tensile strength is applied to the bolt. Please be aware of the following, especially if you have an accident. Keep the flying head out of contact with the original fracture surface, and contact the store where you purchased the product or the manufacturer. If the fracture surfaces are aligned, it may not be possible to accurately determine the cause of the accident and guarantee may not be possible. If the bolt breaks, do not align the fracture surface in the same way. We may not be able to receive the warranty. The screw does not fit in the screw hole. 雌ねじと雄ねじの直径サイズ、ピッチなど規格が異なっている場合があります。 ねじのピッチ（ねじ山とねじ山の距離）とねじ直径を再度計測してください。 計測したら弊社のお問合せメールでお問合せください。 （よくあるサイズ間違い） 並目ねじと細目ねじ・・・ピッチが異なります。 ウイットねじとユニファイねじ・・・ねじ山角が異なります。 ウイットねじ（ユニファイねじ）とメートルねじでサイズが近いもの・・・W3/8とM10、W1/2とM12、3/16とM5等 ねじ頭の十字穴が潰れてしまい、ドライバーで外せなくなった。 ドライバーの先端にねじ外し剤を塗布し外してください。弊社でもお取扱しております。 弊社販売製品「スクリューグラブ」をご利用ください。 六角穴が潰れ六角棒スパナで外せなくなった。 六角棒スパナ（六角レンチ）にねじ外し剤を塗布し外してください。 スパナを回す際、ある程度傾けてください。 短期間でねじが錆びてしまった。 湿気が多かったり、沿岸部での鋼製ねじの使用は錆びが生じ易いので注意ください。 ドブめっきやSUS316L製、チタン製の製品をご利用ください。 ねじが入らない。 ねじのサイズは正しいでしょうか？ 外径が同じでもピッチが異なれば入りません。 ねじ山が傷ついていないでしょうか？ ねじ山が潰れている場合や打痕（加工傷）がある場合は外してください。 ねじの外径は平行になっていますか？ 目視で凹凸が見られる場合は転造不良が考えられます。 弊社商品であればお近くの販売店か弊社までご連絡ください。 ステンレスのねじが締付け時にかじり付く、焼き付く。 コート付きのねじや弊社販売製品の「モリコート」をご利用ください。 ねじでいたずら防止をしたい。 弊社販売製品の「HL」ねじをご利用ください。 六角ボルト、六角穴付きボルトのねじ部範囲はどの長さまでか？ 一般的にねじ部長さは下記の通りです。ただし、必ずしもこの長さではなく最低ねじ部長さとなります。 六角ボルト・・・　首下長さ　～130　ねじ部長さ　2X（ねじの呼び径）+6 130～　ねじ部長さ　2X（ねじの呼び径）+12 220～　ねじ部長さ　2X（ねじの呼び径）+25 六角穴付ボルト・・・　　ねじ部長さ　2X（ねじの呼び径)+12 六角穴付ボルトに電気めっきをしたいが問題ないか？ 通常の六角穴付ボルト（生地）にめっきをした場合、強度区分12.9であるため、水素脆性により折れやすくなるようです。 六角ボルトについてもこれが当てはまり、10.9より大きい強度区分のものはめっきをせずに使用した方がよいようです。 ねじの製法について Most of the mass-produced screws are manufactured by mold molding. Molding a screw with a mold is called rolling. Cutting is often selected for small quantities of custom-made products, large products, and high-precision screws. Screws manufactured by cutting are limited in recess (tool hole) shape and appearance. In addition, there are processing restrictions due to differences in materials. Generally, it is difficult to make screws of the same standard as the sample if the materials are different. Please note that some shapes may differ when requesting the manufacture of screws of the same shape with different materials. (Example: knurling of hexagon socket head cap screw, cross hole shape of machine screw, rounded edge of washer, etc.) Screw cowboy Screw trouble Q & A Screws that live in the present age Bulletin board If you have any inquiries, opinions, or questions about our products or our company, please click here. Privacy Policy | Recommended environment | Link Collection