| Document and Entity Information | Apr. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Apr. 29, 2021 |
| Entity Registrant Name | BARNES GROUP INC |
| Entity Central Index Key | 0000009984 |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-4801 |
| Entity Tax Identification Number | 06-0247840 |
| Entity Address, Address Line One | 123 Main Street |
| Entity Address, City or Town | Bristol |
| Entity Address, State or Province | CT |
| Entity Address, Postal Zip Code | 06010 |
| City Area Code | 860 |
| Local Phone Number | 583-7070 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | B |
| Security Exchange Name | NYSE |
