Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (13.74 USD): BGherra
Coupon (13.74 USD): BG592dca
(CouponsFromChina.com tip: this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
There were country-specific coupon codes published on Couponsfromchina social channels and price alerts. Coupon price may vary by country, because there’re different VAT rates, shipping cost etc. There is a chance that some latest coupons are still working:
Old coupons (from the oldest to the newest): 5f6306, 502C6B, TTxBG10, TOOLS15, TS15prime, 13f142, BG2020NS, BGVDay10%off, BGAFF10OFF, bGhOnEy10, BgcLuBofErtA10, BG1401001
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for 16-68mm Adjustable Spanner.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).